I can get around 5 asics from amazon for free ( the 30$ usb ones), how much would this earn me? If I connect them all to a raspberry and use this setup would I go over the break even point? If so by how much? Would it earn me more if I mine a different coin?
Thanks in advance
You won't ever break even with USB miners, but you can get it just to hobby mine and say you're a "bitcoin miner".
Do it just for fun, and you'll be fine. IN order to profit from mining, you'd need multiple TH/s worth of mining equipment, enough electrical capacity to support this, little to no electrical costs, and the price of BTC to go up.
But if you're in it just to play around, get familiar with the tech behind mining, be my guest.