No idea what the mpg is on the TDI, but I ended up with an '01 2.0L Golf... $10K in 2003, with only 30K miles. I found a few Golf TDI's, but they were a bit more expensive than the 2.0, and there are not as many TDI's to shop around for.
I've been very happy with the 2.0L as a daily driver. The 2.0 has a bunch of 'real world' torque for city driving, without the need to shift gears a lot. It is also capable of some great fuel mileage (see my post
here, or just look down the page) if you drive conservatively.
My expenses other than oil changes and service, adds up to about $670 in two years & 20K miles (50K total miles) for a wheel bearing, left door lock module, and front brake pads & rotors.

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