I have a mk3 2.2 td, my advice would be don't buy a renault if you do not have money to throw at it. The modern ones have too much to to go wrong and do so constantly.
I think the DCI models have big issues with the
valve, older 2.2 td models seem to have fewer issues, but still bad.
Pick something mainstream and popular so parts are available cheap new and second hand, and that you can get a repair manual and wiring diagrams for.
Sharan and Alhambra both use the VW PD engine which is good Galaxy uses a ford unit (not as good)
what about a discovery 300tdi?
comon, very few electronics just a diesel pump, probably not most reliable car but easy (cheap) to get bits and fix? and will run on veg
If you are still after an espace you can buy mine if you want, are you any good with electrics?