As lenebene mentioned SG charges $29K for 6 fresh cycles. If you do not take home a live baby in 6 fresh cycles, you get your money back -- all of it. Most share risk do not give back all the money. You can also pull out at any time so long as you do not have any frosties. When I started at SG (which was the fall of 2009) I would have been able to get frozen eggs for my first cycle and if a BFN it would not have been counted against my 6 tries and it would have cost $25K (as I recall). I would have done it because I would still have 6 tries and I would have had a baby. That said, there were no frozen egg donors that I liked at the time. So we did a fresh cycle in Jan 2010 and that was a BFN but I had 2 frosties so did a FET in March 2010 and I now have an almost 6 month old little girl -- the light of my life. So I only needed 1 fresh cycle to take home my live baby but it was worth every penny of the $29K.
Also as lenebene mentioned, the donor pool turns over even on a daily basis. I actually had to choose 2 donors because my first one went AWOL before my cycle began and I do know that there was much more of a selection when I chose the first donor vs. when I actually chose my 2nd donor. My DH and I actually liked the first donor better on paper BUT it all worked out for the best because we have the baby girl we were meant to have. I would check back on the website every few days and you might find new donors -- we got our donor on the first day she was listed and the match was complete in 2 days for all 3 donors -- sometimes you have to move fast.
I did look at GIVF but when I crunched the numbers for money back it was more expensive than SG and I would not have gotten as much money back. I did not look at their frozen egg program -- I think it was just starting when I was looking.
Good luck with your decision.