Hair extension samples/supplier?

Hi all, I'm fairly new to this forum and to hair extensions, so any advice given would be greatly received.

I'm trying to obtain some samples to compare quality etc but the ones I have approached do not provide samples, but have advised me to buy a set and if I don't like them when received to send them back for a refund. I do not want to do this, does anyone have any advice?

I'm wearing a set from a supplier at the moment, but want to see what else is about.

Thank you.