Comixology has a great sale on Valiant Trades right now. Ends today. They are 50% off which makes your price for the individual issues close to $1 or a little more.
I picked up the trades I'm missing (which is only a few) instead of the individual issues like I had planned.
Anyway, if you want a cheap way to catch up this is it!
COMIXOLOGY VALIANT COLLECTIONS SALE - CLICK HERE