Anything you're going to buy at this point will be a total crapshoot. It's so long since any CRTs have been manufactured (2003-2005) that they won't be at their best. Despite being a large CRT fan, I would caution everyone to look carefully at the alternatives.
After looking (again) at Sony PVMs etc for the consoles I've come to the conclusion my next purchase will be an OSSC, probably also a Gamecube GHCD, and a Dreamcast DCHMI slowly when I have the cash. Some people think it's better than a PVM, others not quite as good, but the only thing you're really missing out on is light gun support. Whilst I could probably find a PVM they all take up space and I want to think of the longer term when all the tubes fail.
So far as PC CRTs go there are three main use cases for this :
Period correct output
Handling unusual resolutions and refresh rates/other beam trickery
Every day usage
For 'period correct output' the original poster would be best buying the £25 15" monitor or applying a shader using a modern graphics card. My first PC monitor on an Amstrad 2286 was a 12" CRT that probably managed 800x600, and on which I completed Indiana Jones and the Fate of Atlantis. Here, the heavy usage of anti aliased art at 320x200 was probably helped by the monitor not being pin sharp. Playing it again with either a high end CRT or a TFT shows the art's limitations.
For unusual resolutions and rapidly shifting refresh rates a high end CRT may not help, as it takes a while for them to re-sync. There are TFTs that are good at handling this, but you have to pick them carefully.
For every day usage, the ability to switch resolutions on a CRT is nice, but TFTs do tend to look a lot sharper.
My two IBM C220ps are needing the contrast and brightness to be pushed higher, and the connectors on one are a little dodgy so I keep losing colours.
Don't even mention the CRT projector, which I need to do a complete geometry and convergence reset on it (a few hour job).
I think I'm going to be moving/retiring one of my CRT monitors, and replacing it with a TFT which is adept at handling unusual refresh rates. At some stage I'd like a modern 1440p monitor too..
If you knew for certain a modern CRT with a long life span and perfect geometry existed it might be a more difficult decision, but everything is now designed for widescreen, and a modern CRT would in any case be damned expensive. Eventually you have to move on.