Buy in bulk and it will reduce costs considerably.
Do not buy 1-3 SP31, order 20-40 then the pricing makes it so you can make profit.
No. You can no longer make your money back on hardware.
Most of the people running miners today, like me, bought them last year. Now that I have them, and they are running, I lose more money by shutting them off and selling the hardware than I do by keeping them running. I will not make my money back unless the price of bitcoin goes back to at LEAST $700. But a small revenue stream is better than nothing at all.
That and also many people just do it as a hobby and for the fun of it. Even if they aren't making any money.