An Appraiser's View

Lamar Jackson's inability to get a contract negotiated is the 2nd biggest story of this NFL offseason, and the rhetoric has me wondering if anyone really understands how this (and home sales/appraisals) actually work? Let me try and summarize it. 
The work that goes into determining the right deal for an NFL contract is enormous. Each potential signee is individually assessed by 32 different teams for their weaknesses and strengths on the field, in the locker room, off the field, in the off season, potential income they will generate, injury risks, estimated number of years left contributing at current rate, and an estimate of contribution at a either an increased or declining rate as the contract ages, depending on the players projection. The team then looks at the entirety of the market, comparable available players, what they are asking for, comparable unavailable players that have recently signed a deal, what were the terms of that deal, and what the team has available to spend. Because each team performs their own analysis each will have their own opinion of a players value. The work and analysis that needs to be done is similar to an appraisal of your home for a mortgage, but differs in that it only takes into consideration what the value is for a specific buyer, which is why some teams are willing to pay more than others. 
Lets look at the contract negotiations from the players side. Most players are represented by a sports agent that either has a long history of successful contract negotiations or works with an agency that does. These agents and agencies do their own research on exactly the same thing the teams do, discuss their results including how they players value may be higher for which teams and why, and come to an agreement on how much they are going to ask for prior to taking calls and offers. Once they have agreed on what they feel is their market price, the agent brings the player to the market. The analysis and agent/player agreement is similar to what an appraiser and real estate agent would do if the property had unique features that would be best marketed to a specific clientele.
  But if all sides have done their homework, why doesn't Lamar have a contract yet? From an outside point of view, it appears to be because Lamar is his own agent, and the valuation of himself done by himself, is at above current market due to his own bias (sound familiar agents?). Although it is possible race may play into some owners or general managers decisions, it certainly does not apply to all of them. The owners are in the NFL business for 3 reasons. Money, glory, and  power. If a player can bring them either of the 1st two on the list, they will be signed. Period. But despite being available for an amount less than what Lamar is asking the Ravens to pay him, not one team has made an offer. That is the fact of the market for Lamar today, and the market is what determines his NFL value.