In the case of the gold market it seems to me that a mechanism to rapidly adjust the toll extracted by the carriers near the gold market might just do the job. Lets walk thru a scenario.
A switch one link away from the gold exchange sees its packet queue for that link grow. It raises the toll on that link and begins to discard packets that lack the toll. Soon the lost connection is repaired by one of the several techniques already described in DSR but not without quick attention by guides to a market that changes more rapidly than had been thought likely before. The scouts and guides must adapt to such contingencies, however. Perhaps they can arrange for real time notification by the switches of changes in tolls. With dollar tolls instead of penny tolls, the cost of the attacker has become dramatically higher but scarcely a hindrance to the legitimate traders.
A more prosaic situation is an attack on Yahoo, which actually occurred about February 6, 2000. If Yahoo charged by DSR payments for their useful services, the attacker would presumably pay the normal toll for his efforts. It has not been a particular problem of vandals buying all of the goods in vending machines.
It occurs to me 2013 Nov that a node might consider packet worths as it decides which packets to drop or return when it lacks the bandwidth to forward a packet and lacks the room to keep it longer. This would greatly increase the cost to the attacker and the monetary benefit to attackee.