Depends on how much time yor going to be sat in them.

Cheap ones around the £80 mark have shit foam padding in them that flattens within a month or 2 and leaves them very uncomfy to sit in.

As with everything you get what you pay for, you may not be able to see it but the foam used is far different in the £3 - £400 ones.

I'd ONLY ever go for fixed if its a track car. Safety being a number 1 priority over convenience.