I want to build a fixed bike, but with a flip flop hub (different ratios depending on weather/area). As it will be my fourth bike, I'm kinda on a budget. Can someone recommend a good but not so pricy hub for me?
Thanks!

When you want it to be flip flop, are you saying you want it fixed both sides, or fixed/freewheel?

he probably means fixed/freewheel which is what flip flop hubs are

Fixed/Fixed Hub

Fixed/Freewheel Hub

Both are referred to as flip-flop, as you can flip both

If you are looking for budget, just see what you can find locally on Craigslist.