I think you mean mining devices such as
Bitcoin USB-Stick Miner bitshopper GekkoScience Compac F 200 up to 350 GH/sThe price is approximately $335, and you get 350GH/s in ideal conditions.
If we compare it to the
Bitmain Antminer S19 Pro 110TH - SHA-256 - Bitcoin Miner, its price is about $2,499. In ideal conditions, you get the 110TH.
110TH is 110,000 GH/s and by dividing both sides by 350 we get 314 while the price difference is about 7 times ($2,499/$335.)
What I am trying to say here is that instead of buying 6 Bitcoin USB-Stick Miners, you can buy one Bitmain Antminer S19 Pro and you will get a return equal to buying about 300 Bitcoin USB-Stick Miners.
All the above assumptions are in ideal conditions and for the purpose of comparison only, and no other things have been calculated and I don't know if there is any altcoin can be mined at a profit using 350GH/s.