Dubious
Rods wrote:
Rods are scepter-like devices that have unique magical powers and do not usually have charges. Anyone can use a rod.
Rod of Wonder wrote:
Activating the rod is a standard action...
88–90 10–40 gems, value 1 gp each, shoot forth in a 30-foot-long stream. Each gem deals 1 point of damage to any creature in its path: roll 5d4 for the number of hits and divide them among the available targets.
So it takes 6 seconds to have a 3% chance of getting 10 to 40 gp of gems. That means if you somehow activate the rod every round for 100 rounds, you on average should have 3 results giving you on average 25 gp of gems each. 100 rounds=600 seconds=10 minutes. So 10 minutes averages 75 gp. A day is 1,440 minutes long. Nonstop use over the course of a day yields average 10,800 gp in gems.
The Rod of Wonder costs 12,000 gp. Permanency on an animated object costs 15,000 gp.
If you buy a rod of wonder and just have an animated object activate it continuously in a safe area, you should be able to collect back your investment in just a few days.
This assumes you aren't presented with target issues, and the GM sticks with the "typical powers" of the rod.