You are looking at the expensive TK standard award tickets which TK will sell until the very last seats are sold. Promotional award tickets would be 30k miles for Economy and 45k miles Business but are incredibly difficult to get from/to LAX even only a few days out (NYC is much easier, try to search for the next days to see the price difference between TK promotional award and standard awards).

To me TK standard awards only makes sense for o/w tickets and if the fares are very high, but I don’t know how you value your miles and how many you have available etc. But 105k miles + taxes etc for a o/w ticket in C/J is insane IMO.

With only 3 C/J seats available now there is a high chance that cash upgrades will not be available (neither online or at the airport). There is a separate thread about airport upgrades with TK but as I recall it from recent posts upgrading is from 1100 to 1500 USD for US flights (the first is airport upgrades and the latter price is upgrade sold in the app/website from a couple of days before dept). So if you are looking for a cheap upgrade to J/C it is not going to happen.