Go on the Jayco website. Build your unit, the MSRP will be listed, take a minimum of 30% off of that MSRP, add destination charge (i'm guessing in the 1,100 range) and that should give you a good idea of what you should pay. ( don't let dealer add any other costs)
Some may say start at 33% and you'll be able to come down to 30%.
If they don't want to sell it at 30% off, then politely say thank you and walk out and head to another dealer. Print out the MSRP from the website, printout other dealers prices(even if not the same unit) to show 30%+ discounts. Carry this information with you to the dealer. I had all my info in a simple manilla folder and when the dealer saw that I did some internet research his very first quote was 29.8% off list.
Good luck shopping.
By the way, that 31RL is a very nice unit!
2016 Jay Flight 34RSBS
2014 Ram 2500 6.4 Hemi, 4.10 axle
2009 Jay Flight 29BHS G2 -Traded in-
2015 Toyota Tundra 5.7 Crew Cab, Traded in