is the price difference worth it?

find out what brand the 2nd one is - cheapo no names wont last that great

I've bought stuff from B and B components before. Always seems like very good quality. However I've never bought a bearing from them.

I'd find out what make of bearing each use.

If you search eBay for "Polo G40 front wheel bearing" you should find one made by SKF, I did the other day anyway. And before you ask, yes the G40 uses the same one.

or price them from tps , i got genuine ones for mine and they wasnt too rude price wisse , saves doing it twice when the cheapies howl

It is always better to check out genuine VW prices - you are (sometimes) in for a pleasant surprise. - Plus, as Seveo says, you are ensured the quality.