I bought this http://www.amazon.com/Ovulation-Prediction-Strips-Pregnancy-Test/dp/B0026995KO/ref=sr_1_3?ie=UTF8&qid=1355348645&sr=8-3&keywords=ovulation+predictor+kit.
50 opk strips and 20 hpt for $16?? How can you beat that? Ok I guess you could probably just find the HPTs if you don't want the OPKs too, but it's still a steal of a deal compared to 1 or 2 HPTs for $10-15 at the grocery store!