Ive been in the same situation, it's very frustrating- the world needs educating. PC retailers are sometimes arrogant with their responses to alternative computer owners, especially us Amigans!
I felt that Amiga retailers generally only stock the status quo but never are brave enough to stock modern spec kit. That forces people to shop at PC stores and take a risk buying stuff that may not work satisfactorily with their Amiga. Once products have been purchased, Amiga owners are marginalised with the service and support they get, because the PC retailer knows nothing about the Amiga platform. It makes us Amigans seem like second rate consumers.
The ethos behind AmigaKit.com is to test interesting products on the Amiga and stock the ones that work well with the Amiga. In addition products have Amiga specific installation guides, Amiga drivers or are prepared for Amiga use before despatch .... oh and we have good prices... this month we have an 80GB Amiga formatted hard disk for £49.99 + shipping