I fully agree that the higher the price of the sold car, the higher the profits, for everything is sold on a "margin basis." Options command a higher margin (result in more profits) to GM than the margin/profit on the "entry level car."
GM did not price the Z-51 so they lose money in it. On the contrary, they make money on every Z-51 package they sell. When, on January 13th, GM first announced the Z-51 content, everyone in the Corvette enthusiast community and in the "car media analyst community" thought it was going to be, at a minimum, a $5,000 option. Most guessed around the $6,000 level. When the pricing was announced on April 26th, positive "shock waves," rippled through both communities, and even late as last week, folks were talking about how much a bargain the package is. Predict a Z-51 price increase for "brand new" orders to $4K as early as the first of the year, and maybe a second price increase for the Z-51 package for the 2015's.
GM had to estimate every part/option "take rate," when they signed their supplier contracts. Considering the number of parts and options, they did pretty well. Unfortunately, every missed estimate is causing significant customer pain due to the constraints! GM clearly underestimated the Z-51 option sales (this package is selling at a higher rate than every Z-51 package they previously offered).
They also seriously underestimated how many folks would step up, purely for aesthetic reasons, and pay $1000 extra for a CF dash piece. And, just as obviously, they seriously underestimated how many would pay $2000 just to look at an exposed CF roof, for the standard roof is also made of CF, weights the same, is structurally the same, etc. (Separately, they probably overestimated how many would select the transparent roof.)
Regarding the comment that "there is no way that there are no z-51 parts," that is accurate. at least some of the Z-51 parts are going in to upcoming convertibles for those who ordered them as far back as August, and/or ordered them with those dealers who have the highest priority allocations. I believe that Z-51 parts are "put aside" for convertibles that are status 3000 or higher.
I realize how frustrating it is for all who have ordered a StingRay with one of the CF parts or the Z-51 package. Each day seems like a week, and each Thursday's constraint report feels lately like a stab in the heart. Hopefully we will get over these constraints soon!
There is some good news lately for those who have ordered convertibles. They are now assigning VINs in the 7,500 area, so convertibles will be coming down the line very, very soon, if not already produced and already at sitting in then "quality control hold" area.