You just can't enter in a bookstore or in a comicstore if you're short on money. Comics On A Budget can help you: insert the maximum price, insert the price of the books/comics you want to buy and this little js application will tell you which books you can buy and which not.
This application is designed with smartphones in mind.
http://alfateam123.niggazwithattitu.de/nonchosoldi/
I suggest you to try the webapp with a phone or a tablet.
This application is tested on mid-power phones (512MB RAM, 1GHz CPU, 4" screen) and with a shitty browser, so... don't worry: if it's fast for me, it will be fast for everyone.