For me the meaning behind an engagement ring is the important factor not the bling factor or if it cost 3 months wages.
For our wedding rings we are going to get them custom made in Germany, as my uncle many many years ago gave me a nice gold nugget from the Australian Gold Mines which I have held on for many years, and think this is the perfect opportunity to use it.
Just for fun I looked up an online seller mentioned previously for just your center stone. At 1.8 carats with the specs you gave, indeed the cost is 38-39K. However if you dropped just a tenth of a carat to 1.7, the price drops to 24K and the difference on your finger would be unnoticeable.
What matters is that the people doing the buying and wearing are happy and feel they got a good value. That's going to vary from person to person.
And quality and certifications are important for a purchase like this which will be worn daily for a very long time.
I also believe in buying from reputable jewellers. I'd personally rather buy a smaller diamond in a super setting, with certificates, from Tiffany's (or any of the jewellers on Bahnhofstr) than jetting off to Amsterdam or the Middle East and buying big rocks. A friend's husband did that ... a 'massive' stone, but frankly looks fake. She's always a big uncomfortable wearing it.
The ring should fit the person for whom it is intended. Big or small. Fortunately for my partner, I like small and discrete ... but even than comes with a price tag. I have only a few pieces which I wear every day and night (only earrings and watch go off at night). On pay per wear it works our cheap (well so I claim!).
It also comes with a preprinted return label so you can return your buy by fedex if you change your mind or want to exchange.
Coray Goldschmitte
Fortunagasse 26 (around the corner from Foto Ganz on Rennweg)
8001 Zürich
Phone 044 211 91 34
He is very friendly, advises on the best solution rather than the most profitable one, also tells you when not to do something and always delivers as promised and good quality. It would be worth while calling him in advance, as it is a one man show, so that he is not open as long as the big chains on Bahnhofstrasse.