By the looks of the stamps with visible faces, it's mostly unsorted "filler".
Some are from eastern European nations (Bulgaria, Hungary, East Germany, USSR etc.) that cranked out huge volumes of that stuff.
Most are very common ones from Korea, Italy, Canada, UK, common US Commemoratives, African nations (Ivory Coast etc.) Many on torn covers.
Don't take it to a stamp dealer - they'll take one look (like I did) and give it right back.
Just one box? "$10-15 tops for the whole thing, box included."
Sure, there may be that rare stamp worth something, but most likely not. Most are "book value" of 5-10cents each, but no one pays that much per stamp. Like I said $10-15tops box included.
Don't want to throw it out? Give to a nephew or niece or neighbor kid to plow through.