At some point after you begin rehearsing as a band you realize, the ability to hear yourself within the mix of everyone becomes a challenge. Turning your volume up creates a domino effect, causing others to do the same and presto!
Just like that, you're deaf! With enough rehearsals like that, hearing loss is sure to occur.
so, you are left with two options, either Invest in an amp stand and a nice set of musician styled earplugs, or some in ear monitors. If you decide to go with the latter, then the question is simply which type, cabled or wireless?
The cabled option is most cases is more cost effective and will certainly get the job done, however my issue has always been the arduous task of setups, maintenance, not to mention the stage clutter it brings, especially if everyone in the band is being monitored.
No musician wants the trouble of setting out / packing up, especially if you're playing 2 - 3 shows a night, which is why wireless is the obvious choice. But they are so expensive right?
While the lines of expense may have been much more defined years ago, this no longer the case as good wireless systems are becoming much more affordable, one must really reevaluate having a cabled setup when wireless can be had for just a fraction more.