It varies by game, since each title has its own currency, rarity system, and item types, which is why each game category on GameBoost lists its own specific pets, skins, or currency rather than one universal item set.

No, you don't need Robux to buy items through GameBoost, since purchases are made directly through the marketplace rather than through Roblox's own in-game currency system.

The difference is scope: game-specific items, like Adopt Me pets or Blox Fruits, only exist and hold value within that one game, while Roblox Limiteds are platform-wide avatar items that carry value and tradeability across Roblox as a whole.

Yes, you keep the items you buy permanently on your account, exactly as described in the listing, the same as anything earned through regular gameplay.