The tractor and loader originally sold for about $21k and the added backhoe about $5.5k. That puts it around $26k new. Even though the tractor is low hours, it no longer has a warranty, so that drops its value by $3k and $1k for the BH. Because the tractor is used. I'd take off another 10%, so that makes the total value I would offer at auction as: $26k -$3k -$1k -$2.6k = $19.4k. A good auction limit would be $19k, but if it were an open auction and I didn't have to submit a sealed bid, I'd start my bidding around $16k and hope to get the tractor for $17k or $18k. If I was buying for resale, I'd not go above $17k. That way I could offer the tractor for sale at $19,995 and have some wiggle room to deal with and still ensure myself a healthy profit.