I have an avent microwave steriliser and between both DD's ive had that many different bottles in it
Like the other girls have said its trial and error and in our case lots of $$
With DD2 i bought her glass bottles...she hates them so now she is loving the closer to nature ones with DD1 I think i bought about 3 different ones before finding she liked Mam bottles
DS loved cheapies so that was good.
I wouldnt be spending too much before bubs comes just get the basics if you want to be prepared