While I expect the price of The Meathook Massacre to come down a bit, I wouldn't expect to see a huge drop at rotation
It hit a high above $200 but has backed off from that high for now
The Ur-Dragon is the ideal leader for a Dragon deck that wants to cast Dragons , which is a stark contrast to how Scion of the Ur-Dragon wants to play
Just having the ability to be a scary threat or be big as a cheap card doesn't mean you are a good tempo card
For every 5C deck looking to optimize their lands, I always recommend running as many dual lands and fetch lands as you're willing to spend, and supplement the gaps with City of Brass, Mana Confluence, Reflecting Pool, checklands, and some basic lands
Cards like Unable to Scream or Witness Protection keep threats on the board but completely neuter what they can do