That can be a deciding factor too, yes. But most people dont really care about agent standings. They only care about the amount of SP you have and which skills you trained into.
This is because people who buy characters over the market aren’t looking for an L4 mission runner. Most people are looking for a good startup toon for things like super ratting or rorqual mining.
You’re free to put one together, but its meaningless. People will pay what they think a character is worth. It’s all about what value they ascribe to, and nothing to do with an actual value on things like standings, which you really can’t put a value on.
If you’re looking for an L4 mission runner, you may be willing to pay more for a lower SP char who has standings than someone who is buying an SP farming character and doesnt care about standings.
As I said before, it’s up to the player to put a price he or she thinks is best.