Since the only thing you can spend on tc is on cosmetics for your tori, there should be item power-ups in the game, example:
Tori-Shoes
-Increases the gravity of your tori by 1
Brass knuckles
-Increases point damage by 1
etc. etc.
but, I see a lot of people complaining about unfair disadvantages for people who don't have the amount of cash for the items, so they should have a server option to enable powerups or not.

Nope, nope, nope, nope, nope. Toribash is good as it is. Why should you ruin it?
Everything is fair now, if you'll add all this shit, Toribash will be ruined, it will be unfair.
Not supported.

It must cost like 10,000TC

And you could only get one which would last for lets say a YEAR
something like a booster of tori
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I am with Defflex it might ruin the game though

But why not the brass knuckles idea (like the kiai) but it weakens opponents body parts by 1%

No no no no no. The beautiful thing about Toribash as it is is that everyone has equal potential in every single match. The only thing you ever gain that helps you fight is experience. With things like this, older, and more specifically richer, players would be able to start a match with an immediate advantage over their opponent, which completely defeats the concept of a fair fight.

Then a 2nd dan buys all the Knuckles and max his points.One shot a white belt.

If you want to add power-ups to the game you have to make sure that they're balanced. For example, if you have an item that increases the damage you do, that same item should make your own tori easier to break. Something along those lines.

If your suggestion were to be implemented as is, the rich members of the community would have the upper hand as opposed to the more skilled.

^ So you mean,whenever you increase your point,your tori is more easier to break.
That would balance the game.

This would be my best answer. TC is truly ment to be fun currency and able to actualy make money off the game. Now the reason being unfair would suck is because have you ever been in a differnt game and there was an admin in a server? You know how much people dislike powers like that? Toribash is anti arrogant. ^ I don't mind power ups but you still need the skill. But seriously, it would be cool to have more variety than the huge amount toribash already has.

The game is mildly interesting because both uke and Tori are almost identical. And you want to remove the only trait of this game that relates it to an e-sport.

I have 34,000 games played. What do I get? A freaking bazookie to one shot you because I've played 11x more games than you lol

The name says it all, character upgrades. It would be great if toribash introduced upgrades to people allowing them to say have stronger fists, Harder abs, firm butt-cheeks(lol), or even have the ability to see what type of move the opponent is using and they will be able to counter it effectively. The possibilities are endless. This will be great for first time players so that they have a chance at stacking up against an experienced player.