endymio, several of the key points you expose here, are only in theory. while it's so very cool that you're eloquent and smart, that just doesn't happen in reality, not as a rule, while it's obvious that there will be cases where it's exactly like you say. when EU and others introduced legal efforts against scalping, more was involved than the basic argument from economic theory you present here.
when in London, UK, you tried to buy a ticket for a grand concert, for example The Beatles' Paul McCartney, you'd see that there are many dates. maybe even 30 for such names, over several months. scalpers would then buy all of it, and it would appear on one particular website that received much hate and legal action over the years. and then performers would eventually hold their concert, with a half empty hall, because for most people tickets were far too expensive.
a 60GBP ticket would be up for sale for 1200GBP for example, and the scalpers' resale website would visually and through their technology create a false impresson that there's only one or two tickets available, so that the customer would actually think that the demand is huge, and that they have to pay 1200GBP for a McCartney ticket, instead of only 60, thinking it's their only chance to see and hear him, because, well he's old. O2 was the venue, I believe that its capacity is over 20,000.
same thing happened to me several times, for a Royal Albert Hall concert, and ATP finals in tennis, resale prices were just unbelievably high, and a lot of seats would remain empty, not just here and there. it's easy to understand why, as the graph of scalpers' profits doesn't fit into the graph of whatever interest the seller has, and obviously the buyers. many things have been tried, only one or two tickets per buyer, Wimbledon has a shuffle for example, names on the tickets etc to fight the situation. eventually legal efforts gave some fruit.
it isn't true, or real, that sellers always want the highest price, just as it isn't true that buyers always want the lowest, and it isn't true that scalpers' price will reflect the theoretical fair market value as you present it. there's huge space for discrepancy there, in any point in time, and particularly over time, as new behaviours are created.
theory is cute, with nicely rounded edges, but it isn't real.