some things to consider...
actually, stat bonuses can go beyond the standard 50% of level requirement rule on lvl 15 and lower equipment as well as King Marlone and Zombie King weapons. otherwise, the statement above holds true.
for the betterment of the selling/buying community use the term "Godly" when selling items with near max stats in multiple DESIRABLE categories. for instance a lvl 60 hammer with 30dex 30int and 30str would probably not be considered "Godly" since END/SPR are typically the most desired categories by clerics.
pay attention to the market, see what prices other vendors are charging for similar statted equips. don't be afraid to ask for advice, ask your friends, ask your academy members, ask your guildies. there's a wealth of information and advice out there if you're willing to just seek it out.
prices may vary a bit from server to server, but it's really hard to say.
premium prices should be given to items with END stat bonuses near the max for that piece of equipment.
Typically these are the categories I desire for each respective class:
Fighters - END, SPR, STR, DEX
Mages - END, DEX, SPR, INT
Clerics - END, SPR, DEX, STR
Archers - END, DEX, SPR, STR
that's my take on it anyway.
