One advantage of not having the condo title in your mother's name is that you don't have to deal with the Medicaid look-back period should your mother need those services later. If neither you nor your brother will be living nearby, you might want to consider a condo or apartment in one of the developments that provide "aging in place" services.
Please inquire further about why the HOA fees are so high. I can think of several condos in great locations with fees in that range and it's because the HOA is in financial trouble.
You are facing some tough decisions. I wish you and your family the best.
I'm not strong on HOA's to bein with; but $750?!
Understanding that I am not an Attorney, nor am I a CPA;
I would buy the (house) myself and just let her live in it: Then, if and when, you don't have to worry about inheritance taxes, probate, or any of that stuff.
I would keep it simple.
Good luck and may God bless