I've wanted to try out a diesel, but there aren't common on the used market. In the new market, they sold at rates lower than hybrids here, and that might be counting the quasi-commercial sized trucks.
When available, used diesels used to command a premium. That likely changed with fuel prices. On the east coast, diesel is over a dollar more a gallon than our low octane gasoline. The price difference may be smaller on the other side of the country.
The last year for the TDI Jetta was 2015. Its EPA rating is very close to the 2022 1.5L's. Even with considering the EPA anti-diesel bias, and favorable to diesel route, the diesel model will likely still cost more per mile than the new gas model.
For the OP, the 1.5L does have start/stop in addition to any other improvements over the older 1.4L. That will help with city efficiency. Then the displacement difference isn't huge, and can be less as those posted numbers are rounded. We talking about a difference in 3 to 4 shot glasses.
Diesel is getting more popular by the day here as fuel prices soar, and petrol is now more expensive than diesel again. Grants to electric vehicles have also been slashed, quickest and easiest way to save money at the pumps now is to switch back to diesel.