I have used range finders and range finding binoculars. But I would nt buy a pair. I dont think they are needed. Get to know your ground. Use google earth and use that to measure key distances. Also take two white painted sticks. Measure the length of a deer and then tplace these sticks in the ground. Pace back 200 yards and get to know how they look against your reticle in your scope and do this at various magnifications.
Next time you see a deer - if it looks smaller than the distanc of the two sticks then it is too far.
Sight your rifle 1” high at 100yards and a centre of shoulder aim point is good for 250 so you have a reasonable margin for error.
Cracking guidance but I'm sure you've guessed the charge heading your way from the SD young bucks:

Cheers!
K