From experience I know that
Preseason NFL much like preseason baseball, Preseason NBA and NHL are restricted as to wager limits and wager options in relation to regular season action in the same sports at many shops.
Books widen betting menu's once the teams start to play for real. The same can be said of limits on preseason games vs. regular season games. No doubt you will be able to bet higher when books know the first string for both team will be playing the entire game for both teams.
Some of these game you will see marquee players only making a brief appearance and then give way to a back up. Anything is possible when it comes to 2nd half lineups.
wil.