Amazon.com has Ives by Schlage Flexible Door Stop on sale for $1. Shipping is free with Prime or on orders $25+.

https://www.amazon.com/Ives-Schla…284&sr=8-6
Brand:SCHLAGE
Mounting Type:Baseboard Mount
Material:Alloy Steel
Item Dimensions LxWxH3 x 1 x 1 inches
About this item
Utilizes heavy gauge spring to maintain rigid protections
Simple to install: Only a screwdriver required
Made from burnished wrought steel
Model number: 63F-619E