Two servers with 64GB RAM each and a few TB of storage can easily run a thousand full BTC nodes. This isn't a big expense, ...
If SPR node ops can run a thousand BTC nodes for a few $ a month each, so could BTC zealots,...
I tried installing as many daemons as possible on a 24 GB RAM server a few months ago.
I was only able to start about 15-20 of them before running out of RAM.
(And most of those daemons were for small altcoins that didn't have the high verification needs of BTC (lots of CPU))
1000 daemons on 2 servers is not possible, you need to spread this over a few dozen servers, plus it will probably cost you a few thousand dollars a month.
Also, with SPR we will have the requirement that every node needs to run on a unique IP.
So having enough servers to be able to run 1000 daemons is one thing, but having unique IPs for every single daemon will cost you a fortune. Every month.
I can fit 10 daemons comfortably on a 2GB server with a low end CPU. I'm talking about *coind, not *coin-qt. Maybe you'd need 3 64GB servers... point is it aint much.
And bitcoin nodes can be run on IPv6 addresses, either directly or via a tunnel. IPv6 addresses are practically free.