yes and no... when was the last time you saw a fight where guys took all their clothes off and wrestled around in their drawers? If a guy wants to take his shirt off to fight, then kick him in the dick when its over his face and run.
BJJ is good for 1 on 1 fighting on the ground, not when the guys friend comes up and soccer kicks your head. Remember BJJ has rules, street fighting has animal instincts coming out.. biting, eye gouging, fish hooking, etc. Choking someone out and throwing an armbar is much harder when your opponent is biting the hell out of you, just ripped your ear off, slams your head to the pavement since you pulled guard, or even pulls a knife out while on the ground.
and BJJ gi's arent' much.. I've seen basic ones as cheap as 40 bucks, or splurge on a lucky brand one for 250.