The biggest reason people opt for a used transmission is the price tag. One can easily find a good-condition second-hand transmission online or through personal contacts at only a fraction of the cost of new ones. If you do your homework, you can easily get the same quality that brand-new engines offer but at much lower prices. Also, you often get a warranty with second-handed transmissions, so if something goes wrong after the purchase, you can just take it back and get it fixed. Convenient shipping is also available at a minimal cost.