Rescue situation

While hanging around the pet shop the other day, I fell in love with this one rat. He was a male grey hooded in an extremely overcrowded and barren aquarium. He had the sweetest personality and I playyed with him for well over an hour. One of the clerks saw that I was playying with him for a long time and assumed that I was buyying him, sayying, "Its a good thing you're getting him, otherwise he'd end up snake food." Im under strict orders not to bring home any more animals, so this basicly wrecked me. Ive been back to the store to check on the rat every day since, and have convinced them not to sell him, at least not for food. After searching for someone to take him, I finally found a friend who gladly agreed. Im going to buy him, his cage, and his food, but he is going to live at my friends house. There are a lot of rats there that will end up as "snake food," but its a little personal victory to me to save that one. One problem I have is that I can not afford a cage. I have the old makeshift one that I used for my rats before I got their cage, which I will give my friend till I can buy her a real one, but its not very good at all, and lacks good ventilation. I dont know if she'll agree to getting him a companion, either, but at least he wont die.