A couple of questions....... If you kill bates does chukka leave your party? Its said that to buy the mansion is between 50-100 thousand depending on what stats? just haggle? Parmanian
I'm pretty sure that if you have Chukka in your party and attack Bates, he will attack you. Just have him wait outside while you kill Gilbert. It depends on your haggle skill. I wouldn't know about the price as Bates always lives in my games.
Don't Know about Chukka, I'd leave him outside just in case, although it seems like silly extra code - I doubt it - He'll probably just get the standard mad. I don't think you can buy, or have any reason to buy the mansion, although I could be wrong, I haven't done the Appleby quest in a long time.
Someone on the Sierra board said he had Chukka kill Bates, no problem with Chukka leaving that way. To do this I think you need to insult Bates, perhaps by talking about his labor relations, untill he atacks you.
As long as you let Bates strike the first blow against you, Chukka should have no problem with you dealing with him. Make sure your followers dont attack him either until he gets a hit on you.