Thanks for starting this community!
Few points that might help narrow down the answer:
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How many are you in the band?
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Is your band running your own sound or are you relying on the venue or local engineer?
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Do you have / want to have drums in your IEM mix?
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What's a realistic price range for you?
Answering these might be a good starting point.
But for a quick answer, assuming you're just getting aux send from the main mixer,
An easy upgrade that's inexpensive would be to use a small mixer with EQ. That way you have SOME means to adjust the tone of the mix.