Let's face it, when walkers come out of the factory, they're pretty. . .basic. Fortunately, there's a booming after-market industry aimed to help you tune your brand new walker to your exacting standards!
First off, you have to have a part. Each part can accommodate upgrades in varying areas. However, each part can only accommodate a certain amount of upgrades based on its Part Level. Level 1 parts can accommodate 5 upgrades, level 2 parts 10, and level 3 parts 15 and up. The only exception to this rule is weapons, which instead use accessories to improve their abilities. A weapon cannot have more than one upgrade per area, however; so you cannot stack Fore Grips if you wanted to.
Price: All upgrades cost the same, starting out cheaper, and getting more expensive as you continue to upgrade the part. The formula is thus: Base Tonnage of the part * (Upgrade Level +1) * 100. Thus, the first upgrade on a Zenislev torso costs 50 * 1 * 100 or C$5,000 The next upgrade, C$10,000 and so on.
Note: When applying weight reduction and carry capacity mods, add together all modifiers then apply to the part. Weight reduction modifiers do not modify the cost of upgrading the part they're applied to.