Lately I've been running into a lot of situations with partners who are in panic mode because a customer has finally decided to act on a quote.  Good news right?  Well not always, especially if the quote is from 3-4 months ago.  And as you already know, offers and incentives can change significantly in that time frame.  So do yourself, and your customer a favor.  Put a reminder in your calendar to check all outstanding quotes at the beginning of each month for any offers that may have been included.  Then check out to look for any updates or changes to the promotions.  You may just uncover a gem while you're out there and save your customer some additional dollars.