Georgian rings on ebay

[Floydian]

Hi there,
I have been looking to buy a Georgian diamond ring for some time now. I would have liked to avoid ebay only sellers however I'm interested in a piece being sold by this seller http://stores.ebay.com/Gems-By-Jewels
Alarm bells are starting to ring now however as I notice how many Georgian rings are being offered by one person and just how similar many of them look, they do however have a good seller rating.
Should I be worried by this, is there a good chance they're fakes?

Thanks for any help!

 

[Sphene]

Contrary to popular belief hallmarking was quite popular in the UK back then (nobody wants to get ripped off) so for me the give away is its not hallmarked .625.

Plus the quality of the gold work is not up to much I would not get much pleasure out of looking at it

 

[Vesper]

The prices seem a bit high based on other items I have seen from the same time.