Travelling to buy would be ok for me , I wouldn't travel to far to sell, If someone knows you've travelled a good distance the chances are they will start haggling the price down, Just some Buggers out there who will try it on, If selling from here I don't think that will happen, lot of good ones on here plus you have the previous posts etc to go by,
About 150 miles would be ok for me to travel which I have done a number of times , Also went on my motorcycle once to pick up a mk1 hw80. Turned out a nice day apart from nearly loosing the gun on way back home.