i think the base of compensation for a number one pick is:
the teams first and second round picks, plus an additional 1 or 2 picks depending on what rounds are negotiated for trade.
using the Washington/Rogers example
a myriad of factors are obviously at work:
what's the loss of talent from Rogers to the next available WR (Johnson, MIA). If it's relatively negligable, Washington may express that they are not willing to sacrifice as much to retain the #1 pick if they are willing to settle and secure Johnson.
Is washington willing to play poker with other teams looking to move up as well?
just a few things off the top of my head.
Only 3 leagues this year. No sense in rooting for everyone in the NFL.