Great idea! But drop the idea of having the ability to "buy a QSO".
Even if it doubled the number of DXpeditions?
Remember, this idea would apply to a relatively few people. No one has to do this.
The problem with the DXing game, as we know it, is that while we may piously resist the idea of a sked, the result is, at present, we rely on the DXpediitoners themselves
to fund the bulk of the expedition costs.
I'm not so sure that's really more virtuous in the end. It is our custom, but I find it strange. Why should the DXpeditioner pay quite so much more than I do to make my DX QSOs possible? They do so at present and we have the number of DXpeditions we do as a result.
If we want more activity, we (or some of us anyway) need to find ways to make people willing to contribute more. Your suggestion is the status quo. We know how that comes out. The DXpeditioner subsidizes us.