You know, Stern's prices were going up long before Jack came around, and if anything have merely continued to rise at the same pace.
In the two years prior to JJP existing, street prices between CSI and Avatar LE went up 36.8%. In the two years after JJP came out, prices between Avatar LE and Avengers LE went up 34.6%.
But sure, let's ignore the identical pattern before WOZ, and blame Stern's business practices all on JJP...