If they could do let say 15 shows(5 in NY, 5 in Chi. and 5 in LA) spread out over two months that could go a long way to do the final farewell.People would pay whatever the cost of ticket,traveling, etc. At least I and a few of my friends would.
They don’t need the money. Plant obviously is not interested. I recall Roger Waters who really burned the bridges with the rest of Pink Floyd realized he wanted to bring the band back at the Live 8 Reunion.
Gilmour was not interested, Mason probably not and sadly Rick Wright died about a year later. Gilmour had said in one interview that Waters mentally beat on Wright and Mason so much that he destroyed their confidence. They needed a back up drummer and keyboard player early in their tour when they relaunched post-Waters.
Being in one of these bands usually becomes just a business arrangement. A lot of people cannot stand being around the others after a while in some cases.