I think original engines are not quite as important as a rust-free, straight body is preferred.

Four-speeds and numerous options (I think AC actually lessens the value) can easily compensate for not having a numbers matching engine (who cares about trans).

Remember, e-bodies are $$$ b/c of the high cost of restoring them as they didn't make hundreds of thousands like mustangs or camaros.

This is how I see it ( I could be wrong, ask my wife   )

People who "collect, are into, invest in " E-Bodies are most interested in how close to Original it is.  If it still has all the major items it left the factory with, it's worth big bucks.  If those parts are Hemi's, 440-6's, 4spd's, convert's etc.   even bigger bucks.  To most, if the major item has been replaced with a non #'s matching one, the value goes down.  If it has been replaced with a different part ( a 440 replacing a 383 ) down goes the value.

On the other hand, people who have a bit different interest in E-Bodies, buy them to race, to just drive, to recapture their youth, etc.  are looking more for potential.  If the body is straight, no rust, major parts they want in the finished car are there, so much the better.  A Hemi clone is a great find, as long as it doesn't cost like a #'s matching original.  A 318 3spd is OK too, costs less and can be converted to a 440 4spd without a whole lot of trouble.  Now if they find a #'s matching car at a "potential" car price  WooHoo  

Of course there are all kinds of people who are a little of both or not at all like I've described.  Me, I fall somewhere in the middle because of the size of my wallet.  But overall, condition plays a big part, however you look at an E-Body.

Just another opinion ( I got lots ),

P.G.

Like PG said, some guys (money no object) buy these cars like they were "still in the box" and either will just have them sit in a garage or sell them the moment someone offers them the right $$$. To me this concept is so wrong and is one of the reasons the cost of this hobby is getting crazy. I do have a matching #'s car but was fortunate to buy it at about half of it's potential value. On the otherhand my Chally was an insurance case, the car was totaled because the dumb ass*s didn't know the value of the car. Aside from a quarter panel, rear valance and a spring shackle repair, the car was stright and solid as a rock. No theyshouldn't mislead people in the advertising, but you can not realistically believe that every seller is a top notch individual (honest), he just wants to sell his car for the most he can get. To most of us "blue collar" jerks (I've been called that) the one thing we hope to find is the car that will require the least shop hours to finish. The body / paint shop is the biggest $$$ in the resto.

Personally ignore the "honey coating" in an ad, if the car is close to what you want in model and price, somehow "look" it over, then make an offer.

I think that the prices have gone wild because investors have gotten involved in the hobby. An average increase of 10% a year is a good investment better than the stock market for the last year or so.  It will be interesting to see what happens at Barrett Jackson in the next week. I think the prices are due to come down. Investors will not be buying but selling. It will be interesting to see if the Nash Bridges car will show up and what it goes for. Last year the cloned Cuda went for something like $135,000 when it's actual value was about $35,000.
As for the seller advertising the real McCoy. It's an attention getter. It's a sellers market right now and buyers are panicking when it comes to the possibility of not getting the car they think they are getting. Its a must have attitude.
I think that ebay is not the place to make a major purchase like a collector car. You are under the gun to buy and don't get an opportunity to check it out properly. Ebay is becoming a place for less than honest sellers to unload a lot of poor quality product for big dollars. Try Hemmings or MCG mags. At least you will have time to check it out.
However having said this there are some honest sellers out there.

I think that ebay is not the place to make a major purchase like a collector car. You are under the gun to buy and don't get an opportunity to check it out properly. Ebay is becoming a place for less than honest sellers to unload a lot of poor quality product for big dollars. Try Hemmings or MCG mags. At least you will have time to check it out.
However having said this there are some honest sellers out there.

Amen CamJam!  Ebay can be an evil place for liars to sell their junk to unsuspecting buyers.  I only buy/sell parts on there.  I don't think I could ever get myself to buy any car through it; there's just so many different risks you have to take with it..  With that said, it's off to look for some more deals on Ebay!

It's not the real Mcoy if the motor or trans do not agree with the way the car left the factory.

 I would say a 383 R/T or Cuda with a 440 now installed would me worth more than a 318 Barracuda or Challenger with the same 440 installed considering body conditions etc were all the same.

I always look at what the car was when new, look at the options and go from there. I'de rather have a 383 R/T with all the power toys and A/C than a 440 R/T that had no options if the asking prices were the same. I would also look at original colour as having an impact on price.
A high impact paint colour would be much more desireable than a brown or a green IMHO.

the real mccoy thing is out of control, but the word Rare is used a ton, according to ebay everything is rare.