tldw; He says he doesn't advocate it but they get away with it by having the community test it out for them in their meta site. Then the community writes up the bugs.
My mind works exactly the same way. Best thing for me is to commit to a deadline and have consequences if I miss. Involve third parties somehow (angel investors or get it approved as a school project). Make a deal with another entrepreneur where you owe him money if you miss your deadline. If you don't produce, don't fool yourself - you're not an entrepreneur just a dreamer.
GoCart gets the local prices from the website itself. Several merchants' websites have a "check local inventory" feature where you supply the zip code to get a list of stores. Check out the video at http://www.biggu.com