It's a long time since I've been in or out of Don Muang airport so can anyone give me any information about the availability of long distance private taxi hire?
Should I just be able to turn up and negotiate one on the spot to go to Aranyaprathet?
(FYI the reason it's from the old airport is that's where we're dropping off a hire car and the reason not to take a bus from northern terminal or other cheaper ways is that there are 4 of us including my parents so comfort and speed is more important than price! Also even though I have spent time in Bangkok recently I want to avoid it with them. Eg I know that a private taxi from Kao San is quoted at 2,500-3,000 baht compared to 300 all the way to Siem Reap on the bus/mini bus but the criteria is different for this journey!).
Yes; you will be able to hire a taxi straight to Aranyaprathet.
But with 4 people you might get problems with your luggage; most taxis have very little space in the trunk as they run on gas and the tank is usually fitted back there. So try and get a van-taxi.
For the price it should be somewhere around 3000Baht.