I tend to not buy base cards online. I grab a few blasters and hope to pull the base cards of the players I collect. The rest I use for trade bait or to give to lil kids. I have yet to add the base card of Andrew McCutchen's 2015 Topps Heritage to my collection. However, in my Quest for 100 new Cutch cards I have added 3 Chrome parallels.
I recently picked up at a card show the Photo variant and Gum Stain variant for $7 total.