I've seen 1959 LPs and 1958 Flying Vs listing at over $150,000. Personally I could see $10,000 for an exceptional hand made instrument, like an older Private Stock PRS or a Benedetto, but I've had a few Les Pauls. . . Nice bridge pickup tone, muddy neck pickup sound (notice I didn't write "tone"), extremely heavy (I think that's why Jimmy Page was always round shouldered with his guitar on), slow neck, nice top finish (sometimes), uncomfortably sharp binding where it rests against you.
I'd keep that money invested elsewhere.
Around here the news people keep talking about a "Real Estate Bubble" that they predict will pop soon and the market will crash or level out. Homes that cost $150,000 five years ago are selling for $350,000 now (and people are actually paying that exhorbinate amount).
Doesn't it seem as though this has happened to guitars, too? I remember ten years ago seeing 1952 Les Paul Goldtop at a music store for $3000 and thinking how overpriced that was. I remember seeing 1950's strats for $5000 and thinking the same thing. Now we're seeing those same guitars going for 10 times or more those prices. I've seen 1980's Charvel's I used to own going for very high prices as well.
Even the EBMM models - the EVH guitars are going up, the older Lukes. I better buy some more guitars. . .
>^..^<