I have the Aquarium Pharmaceuticals Freshwater Master Test kit. I bought it at Petsmart for about $20-$25. It has pH, High Range pH, Ammonia, Nitrite and Nitrate. The kit will last 700 tests. I've probably done 100 so far and the bottles aren't even half empty.
They have it at Big Al's Online for $14, but you'll pay about $8 in shipping. But both Petco & Petsmart have it.
The only thing is, each bottle in the kit has a different number of drops required, i.e. Ammonia 8 drops, Nitrite 5 drops, Nitrate 10 drops.
I love it!
~ Jessica