Am I missing something. If you are just in the process of getting 15K for 8 segments, then the next 4 segments will get you another 10K, and the next 4 after that will get you nothing. You'll need an additional 4 segments to get you to the 60K bonus.

So the question is "how much are the next 10K points worth?" followed by "how much are 35K additional points worth?"

Spending $1000 to get 20 segments and 60K points seems like a good deal on the face of it, but $1000 to get the next 10K seems like a bad deal. (You can directly buy 10K miles for $400.) Spending an additional $1000 for 12 segments to get an additional $35K is a tougher call.

60K points has a retail cost of $2400. But unless you intend to use the points for air travel (and only air travel) 60K points probably has a "retail" (i.e. merchandise, hotels, cars, etc) value of substantially less than $600.

35K points has a retail cost of $1400, at 4c per point.