Heather,
I certainly didn't mean to keep you up at night worrying about your buns. It sounds like you have been giving them a good basic diet. Yes, it is a pain that the timmy hay is more expensive and the veggies tend to add up after a while too. I am hoping that as timmy hay becomes more popular, they will plant more of it and price will go down. I was on bunnybytes.com and they also offer oat hay and orchard grass. I have read in several different bunny magazines and on other websites that these are also an excellent food for bunnies. You might check to see if anyone in the UK grows them.

I found the most cost-effective way to buy the timmy hay is to spend a lot of money all at once and get the largest size available. So I buy a 50 pound bale and although it costs $50 plus shipping, it will also last 3-4 months for 5 bunnies. Of course my pocketbook doesn't like that kind of expenditure but neither do I end up having to go out every week or two and buy the smaller, more expensive bags. Let me know how you do finding timothy and the other hays. You also might check with other bunny owners or rabbit clubs there to see how they are dealing with these problems.... Surely they must be aware of the complications of a calcium rich diet and are finding alternatives. Good luck!