The HOA can come after you for fees incurred during your ownership. If they file a lawsuit, the court will award those fees plus attorney's fees to the HOA. If the HOA puts a lien on the condo but does not file suit, the buyer at the foreclosure sale will take the property subject to the liens, and will eventually pay them (usually many months or even years later when the bank re-sells the condo).
If you are out of the condo, you can quitclaim your interest to the HOA, preventing them from accruing future fees, but that does not let you off the hook for fees incurred during your ownership. (The foreclosure will wipe out their new ownership interest when the bank finally gets around to foreclosing.)
You can always try to settle: they do not have to take less than the amount owed.