I think that the price of the pASLRB is fair.
Most of us are spending lots of $$ on Journals, WO Bounus Packs, 3rd editions of Core Modules, HASLs, not even mentioning TPP offerings.
The eASLRB offered by MMP is a very good deal: Buy once, pay once, no subscriptions. And MMP does provide regular updates as has been proven over the last years.
If the eASLRB is not an option, then I believe that spending the money for a new version of a pASLRB every 3 years or so is reasonable and acceptable. This is even more true, since the pASLRB has proven more practical than I originally anticipated. If handling paper rules of ASL, then nowadays it is mostly the pASLRB versions.
von Marwitz