Most folks have a couple. One of mine is that the best time to homebrew some radio equipment is *right now*. A lot of us old timers mourn the loss of Lafayette or Allied with their doorstop-sized wishbook catalogs. We conveniently forget that we couldn't afford 90% of the stuff in them back then either.
More recently was the demise of Radio Shack. I do miss them for a place to get a part quick on Sundays.
Now let's assume the glass is half full: I recently made a mail order from Digikey on Thursday and it came in on Saturday. Not quite instant gratification, but close enough. Their Schemeit allows my tiniest projects to have a drawn and inked schematic that comes out of the laser printer on my workbench. Were they to try to print out their catalog, I couldn't lift it. How's that for a wishbook?
We still have one local electronics supply. Most towns probably do if you hunt hard enough. The prices are high, but they have to be to keep the doors open. And they do provide instant gratification.
SPICE gives us a quick way to try out our latest brainstorm without needing to order any parts at all. Spec sheets for the most obscure parts appear instantly from that same printer.
And the parts. Oh, my gosh the parts. A complete RF synthesizer on a chip for $7. Computers for $50. Complete VHF low noise amp kits for $10. This stuff was beyond Buck Rodger's ample imagination when I was a kid.
The best time is now.