I am working for a company which has made the transition over the last 20 years from paper drawings to AutoCAD, to Mechanical Desktop, to Inventor, and now to SolidWorks. However unless something actually needs to be redrawn we still use, and update, the paper or AC drawings.  I've spent around 20 hours sorting the piles of paper that built up due to a heavy work load over the last year as it helps me learn the filing structure and the products.  We have somewhere in the vicinity of 20-30,000 drawings in various forms, maybe more since I'm just getting familiar with it.  

What I'm wondering is how to estimate the database size that would result from slowly adding all the drawings PDM to determine if I should be pushing PDM Standard or Professional?  Do different file types affect the record size differently: SolidWorks file vs PDF file?

Thanks