Yes they are better, but not 3 times the price better unless you have a LOT of holes.
Depends on the ground I guess. Here I have spent 1 hour per hole trying to dig them with a 3 point and ultimately had to add water to get it done. With down force I can dig them with ease.
I don't remember exactly what I paid for my bell-tec auger but I want to say around $1500. It was about 5 years ago.
I guess if you only had a dozen holes to dig it wouldn't matter much but if that is the case I would argue you don't need to buy one in the first place - just rent.
The ground is not the same everywhere and in some places maybe a 3pt works but I wouldn't want one here and I have drilled tens of thousands of holes.