I would keep the books you have.
Here's what I do. I have a separate savings account, and I put 20.00, 40.00 each paycheck whatever I can afford that week. You'll be surprised how much you accumulate. At the end of the year I buy the best big key I can afford. If I dont find anything I just let the account ride until I find something. Everyone has their own system, but I just find this one very easy. It doesnt take a big chuck of money from you all at once. And you can still have an impressive set of key books.