I hadn't looked at it before. One article lists a price of $ 456 million CDN but two others and Newmont themselves have $ 393 million CDN, so I'll go with that number.

https://www.newmont.com/investors/news-release/news-details/2021/Newmont-Announces-Acquisition-of-GT-Gold/default.aspx 

According to this article https://www.miningnewsnorth.com/story/2021/03/12/news/newmont-offers-393m-to-acquire-gt-gold/6733.html a PEA was supposed to be completed at about the time of the acquistion, so Newmont, as a 15% shareholder, would have had access to the PEA economics. A comparison with SC:

SC total M&I&I 13.6 billion lbs cueq, 25% = 3.4 billion lbs cueq

Using the metal prices used by CUU in their fact sheet to get the cueq numbers we use cu = $3/lb, au= $1200/oz and ag= $20/oz

GT had an I&I resource estimate of 4.79 billion lbs cu, 8.93 million oz au and 19.22 million oz ag. Using the metal prices above to compare projects I get 8.5 billion lbs cueq. Then I use 85% of that to remove the 15% owned by Newmont to get 7.22 billion lbs cueq. There a number of ways to calculate the dollar value if Newmont was buying out the 25% of SC. I took the ratio of 3.4/7.22 billion lbs cueq from the two projects to get 47% and multiply that times $ 393 million to get $ 185 million, add the $ 50 million value in the JV contract, and get $ 235 million. Divide by 550 million shares to get 43 cents a share, which is about where the market is pricing the stock right now. Let me know if you see any errors. GT no longer has a website so I can't easily check what other potential exists.