Hiya! First, I hope things work with your OE :) However, if you end up going the DE route, I thought I'd throw in a couple thoughts. I'm 7dp5dt atm with our DE embie.
I haven't read up on epigenetics, but I did read a *great book* that really drove home the impact of the pregnancy on the future health/life of your child. "Origins: How the Nine Months Before Birth Shape the Rest of Our Lives." Our RE counselor suggested it. Because we are a same-sex couple, and I'm 41 and assumed my eggs were shot, we basically came down to DE or adoption. We opted for DE and then this book made me want to carry/birth even more than before - the impact of the time in utero is huge. Regardless of the DNA, etc. piece, the fact that I have the opportunity to set this kid up for the best life possible cemented for me that, whether my DNA or not, I am setting the course of this little life with my love for it from blast to birth.
As for the donor, I agree on passing on the pal, but it is totally a personal decision. Fact is, our clinic still charges all the fees for getting her set up, their coordination fee, etc. + the legal fees, her drugs....the savings wouldn't be all that great. We opted for an anonymous donor who was agreeable to having her identity released when our kid is 18. This was a compromise we feel good about - we don't want the 'mystery' of never being able to know, and if the kid doesn't care, great. But if they do, we want them to be able to have that information. We used a sperm donor too, so we went the same route there.We had plenty of offers there - but for a lot of reasons people listed here, it just felt too complicated.
Plus, fwiw, going with an anonymous donor let's you decide what is important to you in your donor - you can go shopping. Kinda. At least we ended up finding that part kinda fun, and the more we looked, the more it helped us narrow things down, and also realize what we didn't care about at all.
Anyhow, best of luck! Your kid will be lucky to have you however they come about :)