The "street" price of diesel fuel should not be a factor in your buying decision. For the sake of argument, let's say the VW got 50 mpg on a gallon of Diesel and the same car with a gasoline engine got 40 mpg. Both have 10 gallon fuel tanks. Say the price of a gallon of Diesel is $3.00 and gasoline is $2.50. A fill-up of Diesel costs $30.00 and gasoline costs $25.00. You can go 500 miles on the diesel and 400 miles on the gasoline. Costs per mile in the gasoline is $0.16 and cost per mile in the Diesel is $0.166. So for that extra $0.006 you can go 100 more miles, in the diesel at a $0.50 per gallon price differential. But I know th real world price differential is much less than $0.50 per gallon, so the costs per mile would be lower for the Diesel engine...............
Yeah, that's what I determined. Plus the VW owners were not convincing me that 50 mpg was normal. Further, the VW was about $6,000 more than my Civic. I've been happy to get near 40 mpg at 65-75 mph typical driving week.
What is the additional cost of the diesel option? On American trucks it's around $6,000. Takes a long, long time to earn that cost premium back.