Deloitte says winning the Football League Championship playoff is worth £120m to Derby and £80m to QPR.
The reason for the £40 million gap is that QPR would otherwise continue to benefit from parachute payments after demotion from the Premier League in 2013 if they lost the final.
Derby hope to return to the Premier League after a six year absence
The value of the promotion play-off to the winners has risen three-fold over the past decade, as the value of television monies on offer to those clubs in the Premier League has continued to accelerate.
"The winners... can expect a significant revenue increase in 2014-15 - their first season following promotion to the Premier League," said Adam Bull, senior consultant in the Sports Business Group at Deloitte,
In addition parachute payments for relegated teams have also increased, both in value and length.
"The vast majority of this uplift will be from broadcast income as the Premier League enters the second year of its greatly enhanced three-year TV deals," Mr Bull said.
"Based on existing distribution methods, even if a club is relegated after one season in the Premier League, it will be entitled to parachute payments over the following four seasons of at least £60m."
Mr Bull added: "The continued increase in the value of promotion to the Premier League provides newly promoted clubs the opportunity to make strategic investment on and off the pitch.
"Inevitably, the short-term priority is usually investment in the playing side of the business, but clubs need to also look to the medium and long-term."
Derby beat West Brom to get to the Premier League last time, but were relegated with the next season with one of the lowest points totals ever. Boss Billy Davies was blamed for keeping faith with many of the team but he was also restricted in who he could sign at the time. The play-off winners are always playing catch up on the other two promoted teams - in this case Burnley and Leicester, when it comes to squad enhancements.
The game might be worth over £100 million to Derby but they might have to spend a big chunk of it if they are not to suffer the same fate as last time.