I bought a load of lab cages from ebay. I don't have a diy bone either! The ones I got are 36cm long, 28cm wide and 20cm high. I did have to buy 30 of them, but they only cost £6 each including the postage. I also bought 10 smaller ones (33cm long, 15cm wide and 30cm high) which I thought might be useful for transport or keeping single bucks in. I also have a couple of mini dunas and a couple of mickey maxes too.
Lab cages rock! I bought mine secondhand from a chap on eBay - probably the same bloke as you, Julie. Mine worked out at about £6 each too. You could have a look at the 'Post Your Set-Ups' thread in environment for some ideas, Kathy.