Cryptocurrency ASICs are highly specialized hardware, currently there are no competitive models on the market in the price range you mentioned.

You may be able to find older, used models being sold for cheap, but those models will cost you more in electricity than they will mine in cryptocurrency. They are no longer competitive with modern models that are much more powerful and efficient.

I would like a simple ASIC usb capable of at least BTC and ETH. Maybe LTC as well

The mining algorithms of these three coins are different, it would not be possible to create a single ASIC that efficiently mines all three.