You guys have my respect - there's no way I could've gone concourse with mine.
However, I think there are a couple of misconceptions, regarding concourse restorations.
Fact: Concourse-level restorations demand that every detail be addressed. I label this as more "mostly true," because it all depends on the level of the car's condition when you first start out. Mine, being a pile of rust in the shape of a Mach 1 would never have been a good candidate for concourse restoration.
Fact: Concourse vehicles only increase in value. Not necessarily so. If it takes you $20,000 to restore your vehicle to concourse levels, and the market value is only $15K, you've just risked losing $5K. Granted, the actual worth of any vehicle is what someone is willing to pay for it... but the market values are usually the point in which negotiations begin. Something to keep in mind is the popularity, rarity, and intrinsic value of the make/model/trim-level of your car to maintain a 'realistic' perspective. For instance (and I'm not throwing rocks here), a 1 of 1 Grandé' coupe will never command the same market value as a Boss 351. All I'm saying is just be prepared for the car to not be 'worth' usually anything close to what you have into it, as Pastel Blue said (I know I have over $40K into mine, and I would never get that back because it's 'just' an H-Code Mach 1 - with a value ceiling around $25K).
Fact: Once you start a concourse restoration, you can't turn back. I totally disagree. You can start/stop/change direction at any time. What you will end up with is whatever you put into it. For instance, if you get everything mechanically correct, and decide at the last minute to throw on a set of Cragar S/Ss with BFGs, you haven't "ruined" anything. In order to compete in the concourse class, you'll need to continue in the concourse direction by removing the Cragars & BFGs and fitting the proper wheels once again. Things certainly get more complicated when you start talking about changing things like paint colors, upholstery, etc.
I'm not trying to dissuade anybody from going down the concourse road. I just know it's not for me because I want to actually enjoy the car after I put that much work into it. With concourse, the ways your can enjoy your car and still maintain its concourse-level/value, are usually different than what most people would describe as 'enjoyment.'