My running costs have been very low. 100,000 miles and the only service visit has been a low-voltage (the small 12 volt, cheap) battery replacement. And, third party, getting new tires. Added my own wiper fluid. That's it. And power is very cheap compared to gas.
When you factor in the cost of incurring the loss of value as the resale price comes down, now you're talking about a real issue. Overall while I've saved on maintenance, it hasn't held value. So maybe it's a wash in that respect. But it's a fun car so I'm happy with it.