Re: How much to pay for an JCM 800 combo?
The days of getting a JCM 800 combo for under $700 are about over. I rarely see them for under $800 on eBay any longer. I paid $550 for mine 2 years ago, and can probably get double that out of it (4212 that is now just a shell for a Jeff Seal monster). You may still find some locally, or in rough shape in the $600 range, but you'll have to look close.
Personally, for a solid, non-modded working amp with no performance issues, I wouldn't worry at all about condition of tolex or grillcloth....if it saved me $200-300 over a similarly priced amp in excellent condition. As long as the wood of the cab is intact. You can have a combo re-tolexed for around $100 with Marshall tolex, and grillcloth can be done for around $30. It would be good as new as long as the amp itself was solid. Even speakers are not that big of a concern. You can pick up GT12-75's (original stock speakers) for $100 a pair or less used all the time.
This is what it looked like stock.
This is it now on top of a matching cab.
For the $$ these days, you're almost better off having a custom one off built by Jeff Seal or Trace. I don't know exactly the cost, but I would guess Jeff Seal could build you a killer combo for around a Grand...
The one combo that you can look at that is still available for $600 or less is the JCM600 combo. That is what's setting next to the 800 in the first pic, and I'm really sorry I sold it. Great, great clean channel, and the drive channel is 85% of what the drive on an 800 is....totally stock. I had no issues with it, and Tom M on the board still owns and uses it to the best of my knowledge. That was a great bargin in a Marshall amp.