Where do you find the components to assemble one?
It's much more difficult today that it was a year or more ago. Everyone is panic-buying and there is very little out there. This is a good thing for guys like me, because I'm an opportunist. When you blow your wad on crazy high-end panic-buy NV and it sits in your safe, unused, for a couple of years, and you hit a rough patch financially, I'll be there to scoop it up at half-price.
eBay, ARF EE, SH PX, and other forums and places. Check Craigslist, etc (very low S/N ratio on CL, but miracles happen). Just keep an eye out, be opportunistic, not in a rush. Look for BLEMISHED tubes (!!!). No one wants blems, and that keeps prices low on them. Unless the blem(s) are huge and dead-center, you won't notice them in general use outside. If you spend your days looks at white walls through your NOD, sure, they'll stick out. Otherwise, you won't even see them after the first night. Shoot for something >1300 FOM if you can, but again that's not necessary for the right deal and is just a ballpark. Don't get wrapped-up in all the 2500 FOM mega-tube crazy talk. Green phosphor is just fine for your first PVS.
Using the above tactics, I've built more than a half-dozen PVS-14's for friends and family that were flat-out AWESOME... and not one of them cost me over $1,000. I built my first two back in 2013 and ran them as binos for a full year until I came off the rails and turned into The Horta you see before you now.
If you wanna splurge, you might have to spend $1,500 on a really nice set with a higher FOM tube that is blemish-free or they're tiny Z3 blems.
Then, spend $100 on a Crye Nightcap with Wilcox shroud. Then $100 on a Rhino 2. Then another $100 on an IR strobe/beacon plus counterweight. Then $300 on a nice SF Vampire or SL VIR II. Then another $280 on a TNVC TOR IR laser.
Then you're fully-kitted for $2000-2500, all-in.
If you have >$5K to drop today, then go balls deep and get a smokin' L3 FWP Vyper or PVS with matched accouterments.
The beauty of doing it on-the-cheap is that you'll NEVER LOSE $$$! In fact, on the few I've built and sold, I made at least 50% over COGS on every last one, which financed better and better NODs and accessories until I decided I didn't need a retirement account after all and having $300K in the world's greatest NV was the wiser financial decision.