I wouldn't get overly excited. When I purchased my small Deere 6 or 7 years ago the deal was something like 18% off sticker for members of a Christmas tree group, same as the thoroughbred discount, same as the Farm Bureau discount. The salesman said he could beat those deals if I went the clean deal route. He did.
The only affinity deals I see that look worthwhile are the ones that say to negotiate your best deal and then take an additional $500 (or $300 depending on make and model), or a mail in rebate for x amount.