3x Rule
Price items at 3 times what you paid. A common reselling heuristic that covers fees (~15%), shipping, and leaves a reasonable profit. Not always achievable — validate against sold comps before defaulting to 3x.
Where you'll see this
This term is commonly used on:
ebaydepopfacebook-marketplace
Put this into practice
Shopfront handles the hard parts of crosslisting and inventory sync so you can focus on finding and selling.