1) how much does it cost to start?
At least the price of 1 GPU or a few hundred more than the cost of a handful of GPUs to build a small rig.
2)how much profit I'll be able to take out from mining?
Here's a calculator: https://www.cryptocompare.com/mining/calculator enter GPU hashrate, wattage & power cost = profit.
3)The best way to start mining?
I'd suggest if you already have a PC get a decent GPU for it(unless you already have 1) & just try mining with 1 card to get your foot in the door. From there maybe slowly add GPUs OR if you're in a position to invest look at building a rig(lots of research) OR many people will tell you you're better off just buying the coin itself rather than spending $ on mining hardware. There's so many factors, power cost, cooling, difficulty.
Most people aren't able/willing to do the research & learn all the ins/outs that can make this really profitable. If you just want to mess around with mining just get 1 card like I said, otherwise if you are really serious(most aren't) you should do about 20-30 hours of research before you drop a few thousand on a rig. Then plan to have at least a part time job trying to keep up.
