R9 380, R9 380x or R9 390, or rx 480?

[TurtleEater0]

I don't know what grphics card I should choose, I have an R9 270 but I think it's causing my computer problems and it's restarting it. I don't want to spend $150 and only get 20 more fps, but at the same time... I want my computer to run. My MAX budget is $350 but I don't want to spend more then $250 because I'm saving up for a car so, I don't know if I should just go big and buy the RX 480, or just buy the R9 380 and upgrade later. Thank you in advance!

 

[mrmez]

What about a 970 from ~$230. Unlike AMD they can still be oc'd quite well.

 

[TurtleEater0]

What about a 970 from ~$230. Unlike AMD they can still be oc'd quite well.

Should I get that over a RX 480? I found a 970 on ebay for $215.