If boost had the products you wanted for lulz or fanatsy etc.

Here's some that I can think of right now. It's obvious that some of these might be OP and expensive.
Lawnmower slot - you can switch to a lawnmower to seamlessly run over bushes in places like wolver dens.
Hunchback shield - Attach a shield of your back like a t3 gremlin and
Teleportation Capsules - Get out of mobs quickly. If you land on spikes, sucks for you lol.
Highlighted Squares - On bomberman pvp, to make sure you are completely on a square, a light underneath you will light up on the tile you are on. (Good
for beginners)
Material,crown,heat Magnet - A long vertical range that picks up stuff you will spend time on picking up yourself. Might be OP in FSC
Can you think of some? Then leave some ideas below!

@GamerTB
Try putting something that the devs could agree with, even though it isn't a suggestion.
Where I can go "WAKA WAKA WAKA WAKA, eat yo face !! " and kill everything by touching them ;P

To the graveyard!
Please, and thank you.
Dynamite vest - Just press the button and enjoy the short invincibility whilst the timer trinkles down towards the ultimate self-sacrifice. Of course, bosses are immune to such attacks.
Soggy boots - Exchanges your step sound to a distinct *splish splash*.
IR-googles - Makes the bottom gate in the arenas transparent so I stop getting killed there.

Processing Module (or Lag-be-gone, Server 1+): gets rid of the pesky lag that ails you.
Camouflage: allows you to sneak behind enemies (esp. Gun Puppies) as long as you're not in their range of vision.
Holy Water: use on phantoms to get rid of them for the entire run, one-time use per item
Guild-Hall Construction Permit: allows for guild hall to be re-furnished. Can only be used by a guild master.
Insta-Office Party: Weakens Devilites, also causes them to loose aggro.
Bug-Spray: Weakens Greavers. Low chance of poison afflicted as well.
OP'ed items are OP'ed.
Chemistry Set - Mix two (useless) status vials to get a random different (useful) one
Mirror Shield - Reflects gunpuppy shots, devilite garbage, etc at a random angle instead of absorbing (not straight back, that'd be hax)
Telescope - Zoom the camera further in or out, or look around the map (ie to see what type of danger room it is before opening the gate)
Scarecrow - Has as much HP and the same defenses as the guy that dropped it, and monsters prefer to attack it instead of the knight (until it breaks)
Red Essence - Totally invincible for three seconds
I really like thescream's idea of a teleport cap/hyperspace button to randomly teleport nearby, although it could easily defeat some clockwork tunnel segments or get the player stuck
Scape Doll: Grants a free revive on use upon death.
300 Energy.