Upgrade as in you have already purchased a revenue ticket or an award ticket? Only certain revenue fare classes are eligible for mileage award upgrades (K or higher). The levels will be different depending on whether you have a YBM fare or an HQK fare. Although that price does not sound right for a mileage upgrade award for a K+ revenue fare. If you have less than a K fare, it's possible they are simply quoting the fare diff between your original fare and business in the form of miles at 1 CPM.

Would be helpful if you could clarify on what you mean by "upgrade". There are currently mileage awards (not upgrades) for D1 flights available for 176K miles roundtrip from select cities for the summer (6/30 - 9/6). These awards have a 60-day advance purchase requirement. They also have a roundtrip and Saturday night stay booking requirement (can't be booked as one-ways). The cheapest one-way awards are 105K miles -- although these have a 90-day advance purchase requirement. The highest award levels are 320K one-way. No real way to combine these with an existing revenue fare (you could just cancel the revenue fare and take a credit for future travel with remaining value).