I think that it depends alot of which unhealthy food your eating in regards to price. About a month ago i found myself eating out alot, not extremely healthy foods pizza, pasta, thai, chinese etc. These meals, for me to be full or close to would cost around 30$ or around 2 dishes worth. At macdonals or KFC or somewhere like that the same could be done for under 15$, but probably alot less healthy. Eating healthier though i find is easier, cheaper and more conveniant. If i go out and buy 500Gm flaxseed for say 8$, 2KG of oats for a couple of bucks, coupled with a shake (which is the most expensive thing about 'trying' to be healthy) ive got breakfast for weeks sorted out. If i buy 3kg of chicken breast for about 25$ or 20 tins of tuna (coles has 90gm tins for 90c) and then buy 1KG of rice for 3$ then boil it and sort it into containers i have smaller meals sorted for about 2 weeks. Now that alone covers Breakfast and 2 or 3 meals a day for say 2 weeks and only would have cost under 40$...depending how ripped off you where with your shake or other supplements (cheaper again if you make your own shakes). Compare that with getting fast food or unhealthy food for that many meals for 2 weeks and there would be no comparison in my opinion.