I'm not entirely sure what you're trying to do?
You travel to the vendor, then back to where you started?
Then you want to return to the vendor a second time?
The map that you get from the vendor search allows you one return trip to that vendor using the same map once you've paid the 1,000 gold.
so say i use the map, go to the vendor - but hey! i forgot a rune to mark and found more stuff to buy there, so i go get a rune, put more gold in the bank, etc. then i go to use the map to go back to the same vendor, BUT it doesnt take me back there, it might take me somewhere i've just been, or back to my house (safe location) and then the map is destroyed and i'm SOL, have to do the search again and get the same map again, but hey - if it's taken too long and i bought the thing... well I can't find it on the vendor search again, so damn lost that vendor location because i was ill-prepared
Paying 1,000 gold ought to buy me one return trip straight back to that vendor but there seems to be a bug.