You're better off keeping one PC for gaming and another for mining; if you plan on using the same PC for both, you're not going to enjoy that video card for very long 
Plus, you have to decide if you wanna mine or if you wanna play video games, and that's always a bummer. But anyway, the gaming PC I have right now cost about 1k, and with the accessories (monitor and stuff), cost around 1.4k. I have no idea if there's any way you can get a good gaming PC for 700, but you'll likely have to build one if that's the case.
Plus, you have to decide if you wanna mine or if you wanna play video games, and that's always a bummer. But anyway, the gaming PC I have right now cost about 1k, and with the accessories (monitor and stuff), cost around 1.4k. I have no idea if there's any way you can get a good gaming PC for 700, but you'll likely have to build one if that's the case.