PH Meter suggestions

I am looking for a new Ph meter (preferably self calibrating, but not necessary) for my Hydroponic DWC Setup. I want something that is around $100 and above all else reliable. Anybody had any luck? Suggestions?

Thanks in advance.

i got this one , works very well but if you already have a tds meter then probably not worth it
http://www.amazon.com/Hanna-Instruments-Conductivity-Temperature-Tester/dp/B002ZG8L58/ref=sr_1_1?s=industrial&ie=UTF8&qid=1316676483&sr=1-1

look into blue lab there the best