We bought our twin nursery furniture today at Babies R Us. We didn't know this going in but they offer a multiples discount - if you are having twins or more, you get 10% off everything you buy in multiples. We saved a ton of money!
We also ordered a Dutalier glider and ottoman and they weren't having their usual 20% off sale, so our salesgirl went and found us coupons for 15% off single items. That saved us even more money. 
Can't wait to get our nursery set up ... hope this information is helpful to others.