Every time i go and look at the auction im disgusted by the types of skills people give their heroes.

1-Everyone NEEDS at least 1 hero with scouting. The uses and practicalities are endless. However, it's rare to find a hero with scouting in the auction house, im not sure if no one who sells heroes upgrades that skill or if their main hero has scouting and they are just selling side heroes they level.

2-Why on earth do you upgrade artificer or healer? These are the worst skills in the game, healing heals such an insignificant number of troops its a joke! And thats only if you live and return from that campaign!

3-Artificer is equally worthless, if you manage to fill up all your artifact slots its past time you had a big battle

4-Knowledge is horrible, master knowledge a 50% increase in exp, say the average person goes from lv 6 to lv 30, well by the end of that knowledge will only have given you enough bonus xp to get maybe to lv 31 or 32. Yet you wasted 6 skill points in knowledge!!!!

5-Master logistics and pathfinding are essential, every hero should have these upgraded

6-Master defender/Master Archery are equally good but both are slightly better than Fighter or Master Cavalry. Upgrade Defender and Archery first, always.

Please follow these guidelines and maybe you can sell your hero in the auction house.
Or better yet, you could auction a hero that has NO upgraded skills, so you can guarantee a satisfied customer

P.S. As for price, 10 gold * level is a good rule of thumb. Most people will pay that if you have good skills