If you want a cheap build just for Dolphin, get a Haswell based Intel CPU, like the i3-4130 and and H87/H81 mobo. You can probably build a set up for $400-500
If you want an overclock-able build, go with an i5-4670K and a Z87 mobo. you can make a good build for around $700-800
If you want an overclock-able build, go with an i5-4670K and a Z87 mobo. you can make a good build for around $700-800