5 days a week for a month to and back is about 1400 miles for me (just over 35 miles each way) That is about 32 gals of fuel or right around $130. (car averages 45mpg).
I never did figure out why the WRX platform gets horrible fuel economy for pretty much an econobox with a 4 banger motor. I was able to get 23-24mpg out of mine and that was it. If I drive normal in my Elise I can get in the low 30s, and it runs fine on 87 octane too.
Since a person has to drive to the van's parking lot, in my case to Trunk that would still be ~14 miles a day or a cost of about $25 month, so it would cost me $155 a month to ride in a van.
Reason I am saying anything is someone messaged me saying I should get on this van run.