That really is a question only you can answer

If yours is great and you use it for work and you don't want to spend money then keep it for a few more years, inevitably you'll end up with rot and your fuel pump will fail at some point.
Newer vans are good if they are looked after.
Knowing what i know, buying a mk7 that has decent mileage and a chequered history means it possibly needs.
Dmf/clutch
Injectors
Batteries
Prv/scv updates
Filter head
Bloody good service
Routine maintenance
Ids is a must imo
So that's a possible 1500+
+labour
+diagnostics
If you can do all the work above yourself and are happy with computers then you'll be good to go
New customs and mk7 euro 5 2012on need a bit less ids since they are Siemens fuel system.
But warranty work is slow progress which hinders you from earning if that's what you want the van for.
Custom door hinges are made from tin foil.
Generally more electronics to go wrong also

However, I'm happy tinkering so i like my mk7 with most of the toys and it drives great

I have listed some of the expected problems with bad examples of the above vans that i know of, they're will be plenty around that are sweet tho so it's not all that bad but it is your quest to find a good 1 and also decide if you are capable of maintaining them.