The context of my question is mostly related to crafting items (with an XP cost) and then trading them with other PCs within the party.
In the case where a Gold<>XP ratio does not scale the same (in you opinion) as character levels progress, lets limit the range from levels 5-14.
If I craft a potion, scroll, or whatever, and a teammate wants to trade for it in a dungeon, should I value my crafted item at equivalent market value (GP) or should my expended XP also carry a price?
I am trying to establish a fair baseline before any haggling/convenience price factors come into play. I want to help my team, but also make sure I am adequately compensated for my efforts.