We don't need that much to be a functional offense. There's only room for 5 receivers on the field at any one point of time. If we're happy with Myers/Byrd/White as options 3 - 5. and I would be, then you only need one of each of WR and TE.
We don't even need to lock down super elite options. It's a deep free agent class at WR. A guy like Marvin Jones, Curtis Samuel or Corey Davis could probably be had for just under $10M per. TE will be harder to find, but the team looks to be in good position to land Kyle Pitts in the draft if they so choose.