It takes in incredible amount of training and experience to consistently disarm someone else. Otherwise, just give them whatever they want. In most cases, fight if your assailant tries to tie you or some else up in your home. They obviously aren't tying you up for your pleasure. They're statistically much more likely to severely injure or kill you.
Legally, you are allowed to use as much physical force, but no more than is necessary to stop their attack. Federal law doesn't require you to run away from an assault of any kind or just let it happen.
Usually the 'robber' has more fighting experience and is much more violent than the victim. Money can be replaced. Be calm, move slow, and try to talk as little as possible.