I'm in the same boat as your dad. I bought a Parker Hornet Extreme package for around $550. That included the rope and pullies for pulling string back, which is easy to use, 6 bolts, strap, quiver, string maintenance stuff, and a scope with illuminated recticle which are nice in low light. Another nice thing about the scope, if the battery dies, you can still see the recticles clearly. It took me about 5 shots to sight it in.
Target is an issue with crossbow, Them short arrows will disappear in the wrong type target. The first 3 bolts I shot are history, somewhere within the target. I learn slow, took 3 shots to figure that out.
Another thing about crossbows, their noisy when you shoot, sound almost like a .22 short going off so you want fast. Even with a fast crossbow, I wouldn't be surprised if a deer beyond 30 deers would jump or duck a bolt due to the noise.
Nice thing about the hornet is that it's narrow so that makes it easier to move around.
Good luck with what ever you choose.