Welcome Dagtar,
Price? Check sales yards on the net for similar vans & prices - this one might be a bit too expensive. Does it have an ensuite or at least a portable loo?

General condition - whether it is "weathered" or has been kept under cover; look for water leaks or signs of them, details of servicing, handbooks. Check the tyres including the spare for wear & tear, when they were made (if older than 6 years, they will need to be replaced). Check there are no spoke cracks on the wheels if they are alloy.

Check the weight if possible - Tare is unloaded as it was when it left the factory(not the dealer); ATM is the loaded weight including gas, water, your odds & sods, tucker, clothing. That is the maximum weight the van can weigh. What extras are on board?

You don't say what the length of the Expana is - single or dual axle, or your vehicle.
Check that your vehicle is legal in being able to tow it - if you have a Mitsubishi, Nissan & some others check for a sliding table that gives what your vehicle can tow in regards to Ball Weight (Mass). You might have a car "That can tow 3500kg" but may be limited to 250-300kg ball weight - meaning the 3500kg van is no longer possible as mostly this weight is nominally 10% of the ATM.

I was told by the dealer I bought my Discovery from that my then Nissan Patrol could tow that van - well he was wrong! He didn't know how close I was to my GVM.

The standard tow hitch is ok for most places - depending on where you want to go. It is recommended that the ball is changed annually.

Have a look through the reams of info in the forum via the Search tab.