I bought cloth diapers and wash and stuff them myself. They were $12-$20 apiece and I've used most of them for at least 18 months and they're still going strong. These days I do 2 wash loads a week. I go through a $15 bag of diaper detergent every 6-8 weeks and each wash load takes me about 20 minutes of active time to load the machines, unload, and restuff the diapers. We use a range of diapers from pocket diapers to all in ones and snap and Velcro closures. No prefolds and safety pins. I bought relatively expensive ones and they've still paid for themselves-and I can reuse them for my next kid. Our nanny and preschool are both with them but some aren't so it's important to check.
OP, if you (or anyone else) is interested in cloth diapering I'll be glad to share more info. I'm not trying to proselytize the world, but I think a lot of people would be surprised to know how easy and affordable it is. It also doesn't have to be an all or nothing proposition. We used disposables for the first few months (though baby #2 will be cloth from day 1). Some families use cloth at home and disposables on the go...lots of options. With twins, I might just use cloth at night initially and disposables through the day. My son used to get bad diaper rash till we switched to a wool nighttime diaper which enabled his skin to "breathe" and avoid overheating.
On nursing, a good double electric pump is pretty much a must for a working mom who wants to continue to nurse, and can easily pay for itself (and may be tax deductible now too) A SAHM can probably get away with a manual pump for occasional use. I returned to full time work after 12 weeks and continued to nurse till my son was 18 months. Along the way I also donated >500 ounces of milk to a mother's milk bank too. Again OP, if your wife is interested in this and wants more info I'm glad to help. I got good advice from my mom friends and am happy to pass it on. I had a bout of mastitis too and it was awful, but I kept up production by nursing only on the good side and pumping the affected one. In the early weeks, formula woul have been easier, but once we found our groove the convenience of never having to pack food for him and knowing I could feed him anytime anywhere was great. And if it turns him into the next Michael Jordan, so much the better