14 CFR 250.5 calls for an airline to compensate you for involuntarily denied boarding for overbooking (your circumstance) to the tune of 400% of the fare (though this is capped at $1,550) per person, so that's a helpful index to understand what benefit there might be holding out.

Airlines _will_ frequently offer voluntary benefits in excess of this amount to maintain good relationships, and gate agents for, say, Delta, can even offer as high as nearly $10k [1], which is kind of crazy: you'd think they'd just fall back on the involuntary limits.

[1] https://www.cbsnews.com/news/delta-10000-offer-to-switch-fli....