This community weekend is too open ended for a definitive answer, it really depends on what (if any) days you missed or what Pokemon you feel you need more of. I could use the candy for Bulbasaur, Charizard, Dratini, Larvitar, and Beldum so I'll be targeting those the most. We also have zero idea how common each Pokemon will be, so expect plans and priorities to shift as a result.
If you fail to get anything with particularly impressive IVs then yes, go with the high-level options to minimize dust investments.