What’s the easiest way to get a perm for cheap? Read desc

I’m level 2678 and I want perm control but i don’t have much money and my parents don’t ever give me money if it’s for the game no matter the cost, I’m 15 and not allowed to get a job so I can’t really make $40 that easy even if it seems like a small amount of money, I have $10 and can buy a 800 Robux gift card at the store and try trading but idk what to trade for with that really that would ever bring me up to a 4000 Robux perm