During game, auctions tend to get less active so I propose new achievement and that would be to change your hero boots X times. Boots have to be different, so reequiping same boots does not count.
1. lvl change your hero boots 10 times
2. 100 times
3. 1000 times
4. 10000 times
5. 100 000 times (you get +1000 reputation points for this 5.th lvl because it is pretty much impossible to buy 100 000 boots)