Currently, vendor is at our fingertips if we have Traveler's Tundra Mammoth. It is convenient to repair, sell junks and buy reagents whenever you need them. If you are engineer, you are lucky to have MOLL-E that you can mail stuffs anywhere every 8 hours.
In 3.2, Bank, Vendor or Mailbox will be at our doorstep if we spend 150 champion seals on Argent Pony Bridle. After Pony Up, we can ask Argent Gruntling to run some errands for us. Don't be slave driver, so ask for service every 4 hours.
Here is how it works: