The motherboard is a bit better and the GPU is a bit weaker, but they're pretty similar. You probably wouldn't notice much of a difference between the r7 260x and the 7770. The 260x is just a rebranded 7790.
I went with an APU because you are on such a tight budget. That being said, you can get a little creative with this and switch it out for a regular CPU & GPU. You could even throw on an after-market cooler and still be under budget ( I recommend the Cooler Master Hyper 212 Evo). If you live near a Microcenter, you could possibly get a FX-6000 series along with an MSi Mobo, you get about $50 off the combo! But, even then, trying to squeeze in a GTX 650 or a Radeon 7770 puts the base total at about $700.
This is the best I could do for you anyhow. Hope this helps!