I've been reading this over and over again for the past month. My book budget is limited and it gets even better with subsequent readings. It's my second favorite Pynchon, next to
Gravity's Rainbow. That, however, is thicker, pricier, more difficult to read, and never available in used book shops.
The Crying of Lot 49 is a must for anybody into paranoid literature. It practically invented the genre. Pynchon stays a couple steps ahead of the rest of the pack by dazzling the reader with his incredibly esoteric academic knowledge. Check this shiz out. It's short, too.