So I've been agonizing over this trip to Austin for a while now. Unfortunately can't get a flight I want at the number of points I want/have, and trying to figure out what best to do. It turns out I'm a shade under 20,000 miles short -- the flight's 40k and I have just over 20k.

My options:

(1) Just buy the ticket -- ~$330.

(2) Buy 20k miles for $350. I have DL as my airline on the Amex Plat, so I
should get a $200 credit, so my net cost would be $150.

(3) Transfer MR points to DL. I could transfer 50k points and get the 20k "rebate". That would leave me with a little over 30k DL miles leftover. But I rarely fly DL so I'm not sure if this is the best use of my MR points. (I only have about 100k so I'm hesitant to use 30k (net) MR points.)

I am leaning toward (2) but curious if people think another option is better. Maybe (3)? I guess I would spend 30k net MR points in that scenario to buy a 40k DL ticket, so that's a net gain. But I also was hoping to use a lot of MR points on a trip to Asia next year and don't want to spend more than I have to... (That said, on my Asia trip, I was hoping to connect and spend a few days in Paris, so I'd probably fly AF and connect through CDG, so parking my miles at DL may not be the worst idea.)

Decisions, decisions! Any advice? TIA!