One could argue the upper contracts bring others up, since an agent can say, well if Morrison is worth so much, then someone just below him should be worth just under his salary.
I do think most high spending teams focus a lot of their spending on just 3-5 players, and then there is a big drop off to the middle and arb guys and then another significant drop off to the pre-arb guys.
Look at the Sox (Luxury tax AVV):
$31M Price
$22M HRam
$21M Porcello
$14M Pedey
$13M Kimbrel
$13M Sale
$11M Betts
$9M Pom
$7M Bogey
$7M Moreland
$6M JBJ
$4M Kelly
$2M ERod, Holt, Thornburg, Leon
$1M Vaz, Wright, Smith, Workman
20 players at or near min salary.
9 players between $835K and $3.8M
4 players between $6.1M and $8.5M
4 players between $10.5M and $13.8M
3 players over $20.6M
My guess is the players would vote overwhelmingly for many more contracts between $6-15M than 7 or 8% over $20M.
I'm not sure raising the low limit on teams would accomplish this, but my guess is it would more than raising the top limit.