I've been treated at RSC & BWH and explored Boston IVF & Baystate in Springfield. I was able to finesse insurance coverage so I'm not much help w/ costs (other than try to get most tests done outside of RE's office so your insurance will cover and look for generic meds - estrogen pills from Target as an example) BUT do want to say I finally was succesful (now 16 weeks with a singleton) w/ BWH with second agency donor. I think they are technically competent but their office operation & support is a nightmare to deal with including waiting room cattle call for ultrasounds and parking headaches/expense -- translation STRESS which you don't need. (I suggest you make use of their chestnut hill ambulatory facility when you can and use e-mail so you have a record of requests/communication.)
RSC support was great. Boston IVF was used by friends. Two negatives - cattle call waiting areas and they require unmarried couples to see a lawyer which is expensive and therefore a barrier to receiving healthcare.
Baystate uses inhouse donors but they don't have a pool standing by. They advertise once they have enough patients waiting. You would save on an agency fee (roughly $6k)but would likely wait longer for a donor. They give first priority to couples without children. Baystate does use vitrification to freeze which supposedly increases your chances with frozen transfers. They DO NOT think outside the box when it comes to treatment. If you are unlucky to fall on the wrong side of the odds - you'll have to push them to be innovative, i.e. consider a cycle w/ part partner sperm and part donor sperm which they were NOT willing to do w/ me. I could pay them for another cycle & donor fee ($7,500) if a second straight partner sperm cycle did not work for me!!!!!
If using a clinic with an inhouse pool, think about the ethnic population living in the area - that pool is likely to be what you have to choose from. For example, in western mass there are a lot of people of polish, hispanic and irish descent so finding a fair or hispanic donor is more likely.
Good luck with your journey and manage expectations from the start. DE is a roller coaster just like OE IF treatment. It is NOT the magic bullet RE's lead you to believe. You need to be a strong advocate for yourself.