Ideas for low cost amplifiers with gain control

I have an idea to run two sets of speakers. One pair will be base oriented, and the other a smaller off-axis pair; both made by the same small, boutique maker. I plan to run them both full range. I anticipate a need to adjust the volume of each (or one) to dial-in the mix between the two pairs of speakers.

So, I am curious what low cost amplifiers that have gain control exist or are recommended.  So I will need two stereo amps. Looking for something low cost or moderate, in the $250 to $1,000 range each.

Because this is still a concept, I’m not able to answer a bunch of questions about set up, etc.… I’m simply looking for information about what options are out there.

Thanks.