Granted, there's several solutions out there. For me, I wanted to create something dedicated, modular in weight... and cheap.
This cost me $3.78.
The good thing about it is you can fill the inside, adding whatever ballast necessary (I used large hex nuts, but could use sand etc), to allow support for heavy resin models! I use Loctites "Fun-Tak" and find it super-strong.
No glue necessary, all these items mean it's a very secure push-fit design (I did glue in my hex nut ballast though)
1 x 1.25" dia PVC Coupling (Ace Hardware item: 43107)
1 x 1.25" dia PVC Plug (Ace Hardware item: 44850)
1 x 1.25" dia Round Furniture Cap Plug