Of course we suspect shilling bidding from time to time, especially with certain sellers, but it's good when it happens so obviously that we're left with absolutely no doubt.
Case in point:
1968 Topps #7 NL ERA Leaders PSA 8 (auction ending today), ravenously bid now up to $125.00
https://www.ebay.com/itm/1968-Topps-...T/363316230824
While other BIN options are available for less than half that price:
https://www.ebay.com/itm/1968-Topps-...8/373318199433 $50
https://www.ebay.com/itm/1968-TOPPS-...T/303921245111 another for $50
For the record, my personal price point for this card is $40.
They violated the first rule of shill bidding: maintain reasonable doubt.
* Edit: and for those "buy the card not the slab" folks, that highest priced card kinda does seem like the slightly inferior one too