If you have a small pool and are willing to drain it and refill when something goes wrong, WalMart sells a six way drop based test kit that is much better than their test strips and much less expensive than the kits we usually recommend. That kit has all the basics, but can't really handle more complex things, like fighting algae, very well.
If the pool is large enough that you don't want to drain it and refill when something goes wrong, then a fancier kit, like the TF-100 or K-2006, is a much better choice.