If that is too much, you could always drink gasoline. You should be able to get over 70 thousand calories of gasoline for that price (regional). The best part is that you will never have to satiate hunger again.
Probably not healthy, but filling, yes.
To the Subway responses: I have traveled to hundreds of podunk midwestern towns for work, and became somewhat of a Subway connoisseur. First off, they are not that great compared to lots of fast food options. I am pretty sure their business model is to be better than McDonalds and that works for them. The next time you are driving interstates through the middle of nowhere, duly note the blue signs that only have Subway and McD's listed as food, franchising gas stations was pretty smart.
They are inconsistent as all get out depending on the franchise manager. I have been to one that the "sandwich artist" put a few slivers of green pepper on my sub when I asked for them. This was on a veggie delight sub, so when I rightfully complained, she told me (quietly) that it was because the manager was in the back and was very strict about toppings. I did not want to press the issue and was on my way. ($3 if you PM me the race of the manager, first 3 correct applicants)
Ever since that encounter, I have tried tried to chat up my "sandwich artist" here and there to get an idea of what their manager is like. I think I might as well look for good local places, but don't have a smart phone and they are rarely just off the interstate, because franchised Subways are run just as erratically, with a much better chance of good food.
I would never buy Subway when I am near local/familiar areas, and know there is better food around.