Cheapest place for Molex and Amp pins and sockets (.62, .84, .93) is Bob Roberts (Especially this month in January where he has lots of 100 for $5 instead of $6.
Cheapest place for the nylon housings: GreatPlainsElectronics. They are moderately cheaper than Bob -- AND you can buy them without the matched pins, meaning they come empty and then you fill in how many you need rather than getting them with full set of pins from Bob (at a higher price since he has to count them all out for each)
Also GPE carries both the lower amp housings as well as the higher amp ones (used with the trifurcon pins) that withstand more heat. But on the flip side, GPE charges over twice as much as Bob on the pins, but does have some special pins for even higher amp feeds that Bob doesn't carry.
Shipping is cheap, starting at $2 from GPE instead of Bob's $9 flat starting point.
Buy from both in advance, and definitely stock up on pins from Bob this month!
Finally, core items like resistors and diodes are significantly cheaper from GPE.. 4 cents for many small resistors vs. 25 cents from Bob.