[Buying]  Where to Buy Beyblade Burst Layers separately

Where to buy Beyblade Burst Layers separately under 4-5$
You mean layers off of complete beys and not RLC?
Likely nowhere. Very unlikely.
I’ve seen eBay sellers that sell a ton of spare parts, but never at such a low price except maybe Dual or God Layers.
Very not likely. I know a seller who sells parts separately, but they are more than you would expect. It will be better off for you to save more money to buy a whole bey.
3.style is trusted (eBay), but most parts are 15 bucks. You’re better off buying the whole thing.