If the bill truly is "VG"= a heavily circulated bill with little or no crispness remaining , some loss of colour or vibrancy, pinholes, nicks/ticks, tiny tears etc.
Catalogue price is$125
If the bill is an Extra Fine to an almost uncirculated=It will be attractive bill, maybe one light fold, sharp edges, a few soft corners, etc
Catalogue price is $250-$450
If the bill is uncirculated=it is never been processed, sharp edges and corneres, no folds, "mint"
Catalogue price is $900-$1200
...but then again, these are
catalogue price ranges, which are like a seller's dream price when the market is hot.
You've asked
Any ideas on how much these are valued at on today's market?
which is far trickier question to answer.
#1 the note is a $100 bill which attracts far fewer collectors and happens to be a denomination which is commonly stashed in people's safety deposit boxes, shoe boxes, etc. True, they're not quite as common as the 1954's but they're still fairly common (esp in lower grades).
#2 the market for higher denominations is soft unless the note has a rare Osborne/Towers signature or is in very crisp uncirculated condition
#3 the market is pretty soft across the board as many North Americans (& world collectors) try to consolidate their investments, etc, recovering from 2008 economic meltdown.
That's the way I would perceive today's market however things could change. You may wish to hold on to it if its better than Very Good (doesn't appear to be very flawed as described by "jvickers" post when elaborating on the condition of a "VG" note).
There could be a surge of interest in the $100 denomination when BOC releases the much anticipated $100 polymer. However, that is assuming that the economy continues to improve and the new series attract a number of new collectors (hence higher demand).