Aztec probably carry some common parts as a convenience to their customers.
My point was that there are dozens of sites where someone can purchase the same items at far less cost than Aztec offers. I used Mouser as an example because they are normally thought of as an expensive option for components, and yet they beat Aztec's price in this particular area. If Aztec wants to succeed, the should revisit their pricing and shipping policies. I would much rather give my money to an independent business than to a large corporation, but not when the price differential is that great (approximately 20% higher). If I can purchase single quantities of parts cheaper than Aztec sells them for, then they need to find a new supplier for their bulk purchases.