Disney will offer incentives to reduce the price from the "STICKER" price, but the bottom line is the bottom line, there is no negotiations below that Bottom Price.
On the resale market you can present an offer to see if the seller is negotiable and your sales agent will guide you to help avoid Disney buying back the package. ROFR only happens if the price is too low and you agent will know if your offer is too low. A good agent will advise you properly.