$25 seems too cheap... but it's very specifically limited in scope, and so for someone with just the right skillset (e.g. getting a thrill out of playing around with matplotlib), maybe it is reasonable...?

Perhaps, with another $25, you could get a web API that accepts parameters, and hosted somewhere free (e.g. Google AppEngine)

Another $25, and a nicely designed (super simple) front-end webpage using that API, also hosted somewhere free.

Different skillsets, modules with limited scope, trivial for the right person, dynamically combined.

EDIT Ah, if you don't get/like solutions, you still lose your money. It goes to charity (a nice way to discourage abuse by askers, and keep the tone cooperative) but needs to be factored into the price. Also, the cynic in me notes that if the founders aren't submitting early-reddit style faux-bounties/answers to build community, they probably should be...