If you are new to GPU mining here is my advice to you.

Do not pay high prices for GPUs with the promise of great returns.
Do figure out how to stack discounts when buying online.
Do not buy anything on ebay unless it is truly a great deal.
Do consider buying a good PSU.
Do buy hardware when people panic sell.
Do not fear buying used, but always buy newer models from companies where warranty transfers such as Evga.
Do your research on the best models to purchase.
Do not sell your coins after the panic. Sell during the rush.
Do optimize your miners. This will pay off in the long run.
Do expect a long ROI at around 150 days minimum. This is not a get rich quick scheme unless you were mining in May/ June. Be willing to learn how to trade coins to maximize profit.
Zcash is your friend.

For science I purchased a bunch of GPUs in June to add to my existing arsenal. These rigs are 75%+ paid off already. If I can do it, so can you. Any questions feel free to ask.