Isn't the current promotion still on with Standard copay at $850? Which is $1700 RT, beats $2k.
Now granted that may be something the OP would have to pay vs OPM for the Flex ... and it sucks to go from a $0 SE copay to $1700 but it's still cheaper than Flex.
And yes, I think the chance of an upgrade from Standard on a TPAC even for a SE is ... poor.

But yes, I've seen similar issues with Standard vs Flex of late. Too much of a difference for me to justify.