Value is relative. Scott catalog value will show you what you might be prepared to pay directly to a stamp dealer.
On the other hand, you can check completed listings on eBay
to see what some collectors are paying at auction.
The Scott numbers for the sheet you have look something like xxxx-yyyy. Take the xxxx and do a search on eBay
for active listings. Then look at the far left side of the web page where you will find a gray column with various boxes you can check. One of the choices in that gray column is "Completed Listings." Check that box and the search will done with no further clicks required.
Hope that helps.