That depends. The calculation of the "cost" is not always agreed upon. If you book for a business class seat, is the 'cost" the amount you would have had to pay for that seat, or, is the "cost" the amount you would be willing to pay for that flight/seat (those can be two very different numbers). There have been lots of discussions on this over the years here on Flyertalk.

Considering you only have 80K miles, you probably won't be able to redeem for a TATL business class seat. You might find a OW that is that low, but it will be really hard to find.

Your best bet for redeeming miles is probably an economy seat. With some searching, you might be able get a round-trip Y fare TATL for your 80K miles. Given that you buy BE tickets, you might be able to find that same flight for less than $800, so that would be less than 1CPM. With the era of dynamic award pricing, it is much harder to get high CPM as the award price tends to scale with the cash price.