I loved building it, and love mining, but kinda thinking that with prices the way they are (gpus overpriced, coins underpriced) it might be worth it to flip it, buy some BTC/alts, wait for a pump and then sell and the buy more gpus and build another rig. Might be crazy but I see people asking insane prices for ready-built rigs on craigslist. Thoughts?
If you do love to build then dont tend to sell out those miners you do have recently and as being advised above by most members its better to mine different coins seeing that RX 580 is capable on mining some altcoins in the market providing sufficient hash for you to operate.
As long you can able to handle the electricity expense then just continue on the thing you are doing and talking towards insane overpriced prices of GPU's thats because of the demand on where merchants or even 2nd hand sellers would really use up the opportunity.