Honestly, I think a Critter Nation cage is the best bet. There are a lot of amazing cages out there, but Midwest has me sold, lol. I, myself, have a ferret nation, which would be cheaper, but you'd have to net it yourself with wire mesh since the bar spacing is too large, and ratties can squirm out. You can also check on Craigslist or Kijiji and see if you can find a nice cage for cheap, since it's been used. That's how I got mine
As for food, Harlan Teklad 2014 is one of the best out there, if you look around the site there's a list somewhere out there about the different Harlan products, and the health benefits and nutritional facts of all of them. Also, fruit a few times a week, and fresh veggies every day keep Ratties fat and happy.
For treats, I use yogurt covered rasins, or those little flavoured puffed rice snacks by Gerber, made for babies. You'll find out what your girls like best by trial and error. For toys, I have a few cat toys, the plastic balls with bells in them. My girls chase them around and play. They also have a treat ball intended for ferrets, I fill it with treats and they knock it around the cage trying to get them out. Any sort of boxes, full boxes of tissues that they can tear up are instant nests, wood chews, bird toys/perches. Go look around the site at pictures of people's cages to get some ideas. The majority of the things in cages are either home made or come from the dollar store. Rats are easy and cheap to please. And Hammocks. You'll need lots of hammocks. There are tutorials on the site on how to make easy ones without sewing, and if you're not savvy with a needle and thread, there are plenty of members who sell hammocks and cage liners. Fleece liners are my favorite type of bedding, they're easy to clean, easy to make if you know how to sew, and you can make them out of so many fun colored fabrics.
