For only $15 ? I know a few people doing CAAD technical drawing, all day long. Often just recreating the sketches the structural engineer draw on a piece of paper.
Are you offering to do that manually (prolly outsourcing) ? You know, those paper drawings aren't 4 lines with 2 measurements :-)
Or are you looking into automating that ? That would be a very interesting side-project ... but that would be really hard to do character recog. on hand-written numbers that are all over the place :-/
Cost would be at $10 - $15 depending on house size.