Is this pre-built worth the money?

Solution
It's actually quite good considering the prices of GPU's right now, changing the PSU would be a good idea as the prebuilt ones are pretty cheap but don't just look at the 80+ rating, the unit should have good quality components in it. For a "budget" PSU I'd look at the CXM 550W or better, also if the motherboard is a B350 you'll be able to overclock that CPU.
Nearly all pre-built PC's have 80+PSUs in them nowadays. Hell even the crappy $300 AMD A6 APU my Dad got from Walmart had an 80+ Bronze in it. What I would do if I got that PC would be buy a 256GB SSD and transfer the OS over to that.
 


"80+ bronze" is in no way an actual indication of quality