I'm surprised so many people are worried about libido on cycle. I understand why, but being able to get it up isn't a concern for me. But then again, I'm not getting any at the moment.
Letrozole is the best bang for the buck. It usually costs more, but you can take much smaller doses than what's recommended for normal use (in clinical patients), and in that sense it'll last you at least twice as long as an equal amount of Adex or Aromasin. ChemOne Research sells liquid solutions for the best prices I found. I'm quite confident it's real product too. Rx is nice though because they are a sponsor here and it's good to support our sponsors.