There isn't any cheap good bullets anymore really..
There is alot of FTR shooters on this website including alot team GB f class FTR shooters and this year's European champion so there's all the knowledge you need on here.
You may find its down too personal preference..
Between them they've tried every bullet going..
I think recently the piggy jacks are being tested and some have been trying the A tips.. now these are the most expensive at nearly a quid each π