Most white-grade accessories only required 100 units of iron ore to craft. Upgrading from Level 1 to 2 costs another 100 units, and from 2 to 3, 200 units.

By that logic, each level-up costs an additional 100 units of iron ore.

Most green-grade accessories, on the other hand, required 500 units of iron ore to craft. Upgrading from Level 1 to 2costst 200 units, and from 2 to 3, 400 units.

Each level costs an additional 200 units of iron ore.

Of course, this wasn't an absolute rule.

Some special accessories, like "Carriage Steel Armor" and "Windfire Wheels," cost more to craft and upgrade, especially the "Armor." It was the most resource-intensive accessory he had ever seen.

To this day, he hadn't even seen its Advanced Effect. He had no idea when he would have the honor.

Damn, it was a resource hog.

The "Train Auxiliary AI's" Level 5 Advanced Effect was "Hive Mind."

With each upgrade, the AI's intelligence increased, allowing for faster communication with the Train Captain, and its computing power and information processing capabilities were also enhanced.

On the train, this manifested as the ability to control more accessories simultaneously, such as controlling the oxygen production speed while deploying the Search Radar and using the heavy machine gun to lock onto enemies within the radar's range.

The current trend for the train was that most future accessories would be controlled by the "Train Auxiliary AI," so upgrading its level was extremely important.

And after upgrading it to Level 10, he gained a brand-new Advanced Effect.

[Train Auxiliary AI Level 10 Advanced Effect]:

Capable of network intrusion, decryption, and bypassing most network firewalls.

"Network intrusion?"

Chen Mang's brow furrowed slightly. This world had an internet, but it was the damn apocalypse. What operator would be responsible for maintaining the network? The network had collapsed long ago. This Advanced Effect felt completely useless.

But...

Soon, he fell into thoughtful silence again. There was no network on the wasteland, but maybe there were still some connected places in high-level regions. It might be useful in the future.

Anyway, having it was better than not.

It was better to have a skill and not need it than to need it and not have it.

It was like most people learning to swim. They might never fall into the water in their entire lives, but if they did, that skill would become their last lifeline.

After upgrading the "Train Auxiliary AI," he turned his attention to the "Auxiliary Omni-Wheels."

This was a special accessory.

It wasn't among the twelve craftable accessories for a Level 2 train, but he remembered it vividly. Back when he was a slave on Boss Kun's train, it was precisely because Boss Kun had been unwilling to craft this "Auxiliary Omni-Wheels" accessory.

That had made the train less agile, and when they were about to be surrounded by a zombie horde, he had been forced to abandon all the carriages and flee alone.

The effect of this accessory was simple: it greatly increased the train's flexibility, allowing it to make tighter turns with a smaller turning radius.

The price of crafting the omni-wheels was not cheap.

Crafting one such accessory required 5,000 units of iron ore. No wonder Boss Kun had been unwilling to do it; it was indeed quite expensive. But there were no subsequent upgrade costs; it was a one-time expense.

This accessory couldn't be upgraded.

Its level automatically matched the train's level. For example, a Level 2 train's omni-wheels were Level 2.

He had tried.

Even with his Level 0 clearance that allowed for infinite upgrades, he couldn't upgrade this accessory. It simply didn't have an upgrade option.

As the level increased, the train's turning radius would become even smaller.

After crafting it, three rollers similar to an airplane's landing gear appeared at the bottom center of each carriage to assist with turning.

Besides that...

Chen Mang's eyes narrowed slightly as he looked at the other accessories he had never upgraded. Ever since he had experimentally upgraded the "Train Radio," an unremarkable and almost worthless accessory, to Level 10 and obtained the "Remote Trading" Advanced Effect...

He was full of anticipation for these seemingly insignificant accessories.

Even if nine Advanced Effects were useless, as long as he got one like "Remote Trading," it would be a huge win.

If nothing else, he felt that besides him, no one else on the "Ironridge Wasteland" would bother upgrading the "Train Radio." After all, upgrading this accessory had no apparent effect.

After scanning the control car, his gaze fell on the "Binoculars."

This was a white-grade accessory from when he had a Level 1 train, one of the seventeen craftable accessories. It was a single product, like the "Single Bed," not a production line. Crafting one pair of binoculars only costs 10 units of iron ore.

It was a real bargain.

Before he had the "Search Radar," the binoculars were almost his only means of scouting from a distance.

After getting the Search Radar, he hadn't used the binoculars in a long time. He had only just remembered this accessory while looking around the control car.

Crafting it only cost 10 units of iron ore, so upgrading it was even cheaper.

For just 550 units of iron ore, he upgraded it to Level 10.

After the upgrade, its visible range was farther, and the image was clearer. Of course, it couldn't compare to the Search Radar at all. The Search Radar could even see the faces of creatures and monster information, hidden information the binoculars couldn't provide, not to mention seeing enemies deep underground and inside walls on the radar.

After upgrading to Level 10, he also gained two Advanced Effects.

[Binoculars Level 5 Advanced Effect]: Displays the level of any monster that appears in the lens.

[Binoculars Level 10 Advanced Effect]: Enables thermal imaging.

Both Advanced Effects were quite average, basically simplified versions of the "Search Radar." After all, for something that only costs 10 units of iron ore to craft, you couldn't ask for too much. And upgrading to Level 10 only costs 550 units of iron ore. At that price, what more could you want?

But...

This thing was quite suitable for novice Train Captains.

Chen Mang, who had casually tossed the binoculars aside, was about to continue inspecting the other uncrafted accessories in the train when his gaze fell on the sound system. He suddenly remembered something and picked up the binoculars again.

The first Advanced Effect was at Level 5.

The second was at Level 10.

And at Level 20, a third Advanced Effect would be unlocked.

Currently, none of the accessories on his train were at Level 20, and none had a third Advanced Effect. A thought had just occurred to him. If he upgraded this accessory to Level 20, what would the third Advanced Effect be?

Of course, it was likely to be "None."

Just like the "Headlights," which had no Level 10 Advanced Effect, some more basic accessories didn't have many advanced effects.

But since the "Binoculars" accessory consumed so few resources, it was worth experimenting with.