They do have like $20M+ in cap room this summer. I'm sure we'll get a good piece or two, then.
But you said it - why overpay now? Why give away a first round pick? Or Grant? Or Hernangomez?
This is the time to be a little patient. See if the team can play better the rest of the way, then re-evaluate in the summer.
If Afflalo and DWill opt out and we chose not to keep them, we'll have $35M in cap room and Melo and KP (and Rolo and a few other solid pieces). Go from there.