I'd agree 2 Part was a good way to control your Calcum and Alk, this should keep your pH at normal levels. I'll usually use 2 part to get my tank where I want it. Then use Kalkwasser in my topoff to maintain the levels. After testing I'd determine how much of calcum and alk to reach my desired effect.
This is a FANTASTIC calcuator for calcium and alk adjustments! It will tell you how much to dose, of course don't dump it in all at once. It even has explainations of what's going on with your tank chemistry wise.
http://reef.diesyst.com/flashcalc/flashcalc.html
You can even make your own 2 part, http://reefkeeping.com/issues/2006-02/rhf/index.php So I would say it is cheap, but takes a little on your part to make sure dosing is correct.