For a business scanner which many Fujitsu/Ricoh scanners are I think paid software is easily justified in fact as I mentioned before most instances I have seen them used it is to integrate scanning into a company wide business specific software suite. I haven't had to replace or work with one in several years but last time I did I needed to download from Fujitsu to avoid buying a license for Kofax VRS which if you think that VueScan is expensive just check out Kofax(which appears to be renamed when I google it). The scanners I have worked with in businesses are either cheap throw away from HP or Canon, Large MFP Copiers(leased/rented), or Business Scanners costing on the bottom end $800. The throw away I use the included software as it gets the job done. The large copiers are usually set to scan to email on a network and shoot PDF copies to the individual. The production scanners mentioned so far have all included a license for the Kofax VRS software and then tied into some existing company software for users to scan into where others can view and it can be tied to POs and likes or just in a massive indexed document image archive.
If your scanner somehow fits between the expensive units and the throw away units I think a $50 app is a decent price to pay if it provides the functions you need,