If you're looking for an s5 bro, try to pay it no more than 250$ because there are other models now that can make a lot more bitcoins, but if your budget is limited I must say that any miner is good and will always earn 100+ times more bitcoin than any computer and S5 has low noise and has a fair production per day. Buy it at once if you see it at 100$, it's also got low power consumption. At our lab we just have one of these beauties along with 2 s7s which are way more noisier