1. The relative strength of the town on the template (say, in a Conflux-Swamp pair, Conflux is clearly preferable, but with a -5k start and a +5k bonus for Swamp, Swamp becomes clearly stronger)
2. Who the opponent is and what their preferences are (if we know that the opponent would sell their mother for Kyrre in a Rampart-Barbarian pair, we boldly give more)
3. What the roads are like on the template (on fast roads, in favor of a tempo and breakthrough town like Dungeon, you can give more than on medium roads)
Based on this, there will not be some uniform price in a similar auction against different opponents
P.S. For Jebus Cross, these factors do not matter