Cheap Old Preamps

Luxman c1010 or c1000

or preamp outs of Tandberg or Luxman recievers

A lot of the old tube pres are very decent and the market price reflects that as you say. If you get a tube pre at $100 it is very likely that it will need TLC and drive the price up after purchase even if it is advertised as in "working condition". Caps, etc.. need to be replaced after XXX years. If they have been replaced it will be over your price and if they haven't you almost have to expect to do it and that will cost $$$. $100 is tough for a decent reliable tube pre on the open market.. You could bump into a garage sale special.

The Bottlehead Foreplay is a nice new pre at $150 with lots of ways to mod in the future. Foreplay
If you're afraid of the diy work you probably do not want an old <$100 tube pre as you certainly do not want to pay for service.

I don't know the SS market.

Sincerely
I remain,

Superphon Revelation Dual Mono or Basic
Late '80s vintage. Solid state. Simple design by Stan Warren, originally the "S" in PS Audio. I owned a DM for many years and it sounded great. Original retail on the DM was $400. Pots got scratchy after a while however. If you can find one I bet it would be well under $100.

Good luck

TLHUB

The 3020 mentioned above does have a good reputation. However, I think that you can get the same circuit--possibly for less--in the 1020. I've heard some people who have had a 1020 claim that when they upgraded, they had to spend over a $1000 to get something that's much better.

Thanks for all your responses. I have been keeping an eye out for a nad 1020. I know that sub 100$ is a tough range, esp. for tube gear, but we've also got a friend who's the type of guy who rebuilds stereo and recording equipment just for fun. Thanks again, and I'll be sure to check out some of your suggestions.