You have come to the right place. This forum is full of people who like IBM 5150 and similar machines. And in general there seems to be quite a bit of demand for the the 5150 PC, and other genuine IBM models.
Just be aware that the IBM monitor shells are fragile as eggs and must be packed with extra care when shipping.
Incidentally, yes, the 5150 is the first IBM PC and what common "modern" PCs descended from, although not the first general personal computer.