I contend that it's still cheaper to make something like that yourself.
Sukiya and Yoshinoya are alright I suppose, but personally I try to stay away from fast food-- so I give a perspective of how to save money on a non-fastfood diet. However, I think that fast food is actually quite expensive for what you get.
Again from personal experience... but I haven't had the best luck with vending machine ticket food. I've found it to be quite mediocre and the serving sizes seem to be a little small. It's also really impersonal which I kinda don't like much. Another thing that I don't like is that while it's seemingly inexpensive, you have to order a bunch of tickets to get a decent meal. Like if you order udon, sometimes you'll have to press a button just to get negi on it!
The only thing close to what I've found to burgers in America here is Freshness burger (I live in the inaka so we don't have many choices for that kind of thing). A meal there will cost about 15-20$ when all is said and done. If you simp out you can get by with about 1000円 but that would be like a hamburger and fries (and their burgers are kinda small).
While I've had thin crusted restaurant like pizzas in Japan, I've never encounted a giant greasy the bomb dot com pizza like they have in America. I was at a take out pizza the other day (to get one as a gift for payback to a friend) and it was 1500円 for a "medium" pizza. Their large would barely be a small in America, let's put it that way.
MuRaSaKiiNkI, if you're looking to save money and experience different kinds of food in Japan, I think you're in luck. Trying to save money and eat like we did in our home countries is pretty much impossible here. Making simple things like Curry and Rice is a no brainer. As is boiling soba or udon (noodles) and stuff like that. When you go out to eat take some mental notes and try to make the things that you see. If you don't know the name of an ingredient, you can try just asking... sometimes people will be happy to tell you! My wife and I do it all the time when we go out and she can make pretty good replications for fractions of the cost.
This might give a little extra insight, at least as far as pizza and dairy products go:
Top twenty pricey perceptions of Japanese goods | 世論 What Japan Thinks