Blends definitely seem to save money, but they're nearly always useless to me, so I have a harsh opinion of them. Convenience (having multiple vials to withdraw from vs one) and saving small amounts money aren't high on my personal list for priorities with AAS.
This isn't intended to be offensive, and isn't always the case, but to me blends seem to be more targeted towards, and more popular with, PED novices/intermediates, not people that have been using for decades. Veteran users more often have a very specific idea of exactly what they want to take, partly from a compound standpoint, but especially from a ratio perspective.