Blood Brothers is not really the energiser bunny you make it out to be. It runs cause its
A)A Bill Kenwright production aka extremely cheap as chips weekly costs
B)On the English National curriculum for drama and does a lot of business from schools
C)Its always available at tkts and plenty of discounts
D)If they ever closed that show, the Phoneix Theatre may possibly collapse from years of neglect and the existing set is the only thing holding it together

(okay that last one has been sexed up a bit!)
Jerry Springer did indeed loose a ton of money and part of that was down to disputes between Avalon Productions and the other producers. Was there not a legal case or something? Anyway you are right in that it was empty most nights and one of the first WE shows to hit the £50 ticket price which didnt endear it!