Well, I ended up buying a 10lb tank off a website for less than 100. locally everyone wanted the tank non filled for over 200.... they're nuts. I also found a place I never noticed literally right down the block that will do refills and not swaps.
Next question... Rex Grigg regulator or some other regulator? Also, what is the best way to have the CO2 injected? Should I go DIY and have it fed into the output of my xp3 via a reactor?