Models may have fundamental value, but wisdom on model valuations is a little sparse at this point in history. Same for people in general -- there just aren't more than a few people (and I'm giving a benefit of a doubt that they exist at all) out there making a living by estimating the future earnings potential of an individual. Valuating corporations, on the other hand, is quite popular and there are many thousands of highly-paid analysts who sit around and talk about how much a company is worth, then sell that information to their clients. Actuaries are sort of in the same ballpark and society already frowns on them enough as it is, so while this might be a market ripe for the taking I suppose there needs to be a really compelling reason to pay for the service first. It would make more sense if one could purchase an individual -- I know I've seen Robin Hanson talk about the concept of a society where parents sell shares in the future earnings of their children to finance their education.
But for the moment, even if there were "model analysts" who published estimates on how much a model is worth, it would have little impact on their popularity. Models don't get popular because they have earning potential so much as the other way around. A model who is popular will command higher rates and more frequent appearances. If she is diagnosed with cancer and has 6 months to live then her potential is greatly diminished, but she can leverage it for charity purposes and get even higher rates. Valuation is interesting an academic sense, but for the time being it is a very useless thing to have in the fashion market. This effectively leaves the idea of a model's fundamental value even less tangible than that of a corporation.
Considering the extent to which bubbles form even with the possibility of valuation, the only way that a model popularity market could be analogous to an equity market is if it lives in a perpetual bubble, effectively negating the relevance of the fundamental value. "Reckoning" in the equity markets might be rare, but it does in fact happen. The career of a model, on the other hand, has zero empirical effect by their fundamental value.