I think you are reading this wrong David, the buffs are spells cast by the mentioned class. You don't have to run anywhere to cast them.
So, what you are saying is, if someone wanted to cast a buff on me, I could be 3800m away and only need to be in the party? If so I no longer agree with the idea, or at least your interpretation of it. Most things are sold at spawn, so unless someone wants to go to my place for me to pay for a buff, I'd imagine I will be asking for a GTP or running.