What's a reasonable contract extension for Kamara to avoid possible holdout?

6.25 million a year is really, really low.

I doubt Kamara's agent will even get on a plane for less than $10mm/year as a starting point. Zeke and Gurley each got $15mm/year.

If I had to throw a dart at what he'll end up signing for, it's four years worth about $50 million in total.
IF that is what happens then he can either sit out the year saving the Saints $977.5 mil or play for the same amount and try again next year or walk out as a free agent. With the numerous starters and key contributors that are set to be free agents (and one RFA in Taysom) tat the Saints need to sign plus leave enough space for the drafted rookies and some for emergency signings during the seaon I don't see anyway the team can afford to extend anyone still under contract next year.