Most of those parts are available cheaper surplus. Except for the resonators, which I’ve never had any luck with.
Check out bgmicro.com: you may save enough to make it worth the extra postage. Be warned that, if you’re shopping for panel mount power jacks, the ones BG Micro sells are serviceable, but visibly more cheaply made than the higher-priced ones.
If you do wind up ordering from Digi-key, consider getting some of the chips that are popular in Arduino projects, but really hard to find from other hobbyist sources. Like the TPIC6C595 or TLC5940. In addition to using them, yourself, you might swap a few with folks who want only one or two, and find Digi-Key’s minimum shipping charge painful.
Digi-key has some great deals on mounting hardware, like bags of 4-40 nuts and screws. And these spacers are really nice: run a 4-40 tap through one, and you get a threaded spacer for a fraction of the price of ready-made ones.