The percent off program is intended for full-time equine activities ... there is a coupon program for part-time & hobbyists.
Join first, it's only $55/yr, + you get a good equine insurance policy with the membership & you support the National equestrian teams. Then when you are ready for your JD, call the member perks line of USEF & they will work with your dealer to give them the standard codes necessary for Deere to grant your appropriate discounts.