Unfortunately, the only car I would include in the low cost to own catagory would be the 91 126 chassis car.
The real low cost cars were the 80's diesels especially the manual transmission 240D with manual A/C and roll-up windows.
The 126 chassis is the only one of that era that made it into your 10 year catagory. All the cars built since then have become much more complex and have become that much harder to DIY or even to find a true tech that can keep the cost to only those needed.
Bosch Master, ASE Master, L1
33 years MB technician