I recently got this wireless system and tried it for bass. It works with lower tunings (At least down to A).
The system, however is a bit noisy (the rating reflects this). Overall not a bad choice for that budget.
(update) It broke after 2 years of use, which is to be expected for the price, it's still a good option for those small stages where you can easily get tangled up in cables. Also if you are considering to buy this know that it can pickup other wireless units, which can interfere with your sound. My overall rating is a bit harsh maybe especially at this price point, but it reflects the overall quality of the product, even though it is cheap.