Ah, good catch. And you're right, if I don't like it I'm stuck footing the bill for the return shipping and that 15% fee. Maybe I'll keep this in mind as a last-resort sort of thing and keep looking.
Hello everyone. I'm here with the finished product. I ended up buying this orange diamond from eBay for $200 (3-day shipping included). There appears to be a chip in it by the outer edge, but it was not noticeable when I received it.
I went to David Klass for the setting after recommendation from other forum members. After much discussion and deliberation, I decided on a toi et moi ring. The final design is of palladium, with bezel mountings and milgrain. The white diamond is an old European cut stone, approximately 4.29mm in diameter, a family heirloom. The following photos are those sent to me by David Klass.
I'd like to thank all those who offered me help and suggestions. Have a wonderful holiday season and happy new year!