Ah, OK we are talking different things, I thought you meant MPG when you said "economy" - the TD Cruze is 46 vs 42 for the petrol one.
The difference in price is obviously the other factor. Here TDs tend to cost a little more (less that $6k) but hold their value better, plus in the real world petrols tend to struggle to make their "rated" MPG vs Diesels which often exceed them. Also Diesels tend to end up with higher miles.
Hard also to rate maintenance costs as both have the "regular servicing canary in the mineshaft" - a Turbo
The 2.0 GM TD pretty good IMHO, here taxi drivers take them to 2-300K in mixed driving without major failures.
I'd love to see a comparison of a 5-10 year old Jetta vs a Cruze - how many rattles, how solid, parts cost.
EDIT - We also get a Cruze Wagon and a Hatch!