From what you have said, I do not think you have met this dealer face to face. I'd at least want to see them IRL to know I feel comfortable with their offer. I truly believe talk is cheap ... til you have to call on them!
Will they put it in writing?
Yes, call me skeptical .... though the large cut in price by the seller, does add a red flag for me. I've said my piece ... and now I'll back out of the thread!
Good Luck .... I hope you get the deal and machine you will be most happy with!