Melee weapons

Ball Mark for Wrap assassin cuz why not? Make it 500 credits.

Stun for Sandman, this should cost 300 credits.

Upgrade for the Fan-o-war, Sandman with ball mark, and WA with ball mark, which changes the mini crits of the mark into crits. Costs 300 credits

Deploy time upgrade for Fan-o-war, 2 level upgrades, each costs 100 credits.

Primary weapons

Push force upgrades for the Force-a-nature and shortstop, similar to airblast push upgrades, it gets 4 upgrade levels with 100 credits for each.

Reload speed upgrade for the Shortstop, has 2 upgrade levels, each costs 250 credits.

Increased boost durability for Baby Face's Blaster which increases the amount for damage you can take before losing the whole boost by 75 for each upgrade, this has 3 upgrade levels with each costing 100 credits.

Extra jump for the Soda Popper's hype, 2 level upgrades with each adding one jump for 100 credits.

Secondary weapons

Mad Milk upgrade which heals teammates for 25 health when you hit them with the milk directly. This has 3 upgrade levels and each one costs 200 credits. Each upgrade level adds 25 health to the direct hit of the milk.

Crti-a-cola upgrade which changes the mini crits to crits, though you still shouldn't be using this. Costs 200 credits

Stun for the Flying Guillotine, also costs 300 credits like the Sandman's stun.

Upgrade for the Flying Guillotine with cleaver mark to change mini crits to crits, costs 300 credits

Cleaver Mark for the Flying Guillotine which costs 350 since you don't have a bat to mark with after using the ball like a WA or Sandman.