Hi there -
Welcome! I'm new to the boards, but i've used this site for a couple of years now. I breastfed my adopted daughter and am now preparing to bf our next child (whenever s/he comes home).
Regarding dom - I order it from
www.globaldrug.tv and order twice the amount of 10 mg pills. It's the cheapest I've found online (or anywhere). It may be worth it to you to try and find a doctor that will write you the prescription, though, if it's covered by your insurance. On global drug, they have the pills in different amounts - the more you buy the less each pill costs. I think the lowest price is nine cents per pill.
I'm having the same issue with deciding b/t buying and renting a pump. I was thinking I'd buy the medela pump in style, as that's the most recommended (It's about $250 new), but now I'm thinking I might buy one of the hospital-grade pumps approved for multiple users off of ebay. I'm thinking the Medela Lactina. It's going to be very expensive, but when I'm done with it I can resell it online and recoup most of the money.
I can't answer the other questions - but good luck!