The demographics IS awfully small - in percentage. By far not so in gross numbers. We just have to accept that we are diluted by inert material and ignore said material instead of letting it slow us down.
We live in the age of on-demand manufacturing, crowdsourcing, and world-wide shipping. As long as there are at least few thousands, or even few hundreds, of people who desire something, the something has a chance to get delivered.
Low-cost versions of high-end instruments are in especially high demand; look at the sales of Rigol scopes, a nobody-heard-about brand when they emerged and it took just an eevblog.com review so even a cheapskate like me bought one (and never looked back). And then there are toys like Bus Pirate. Then there is repurposed consumer hardware, like the RTL-SDR dongle that fueled a wide interest in software-defined radio. And easier and easier ways to make your own stuff from components - both on the tool level and the component level (arduino, anyone?); the barriers to entry are going down.
Laser cutters, 3d printers, good digital 'scopes... all getting into the price realm of a better garage workshop. And after a while, the costs will go even lower and the used ones will be even cheaper; there are certain small areas of economy where trickle-down actually works.
Even with restrictions, there will always be a Chinaman willing to sell you a reel or three of fast ADCs or general-purpose SoCs. Drug smuggling shows that even with draconian countermeasures the demand-supply is still the king. And chips don't have any specific smell so drug dogs nor terahertz imaging won't help the adversary - just sand the top, laser a different designation (like it is done with chip counterfeiting), ship, repeat the process on arrival (or even just use stickers); this will minimize (though not eliminate) the chances of getting the shipment caught.