It was like 10 years ago that i quit doing dirt work so prices have really gone up since then. I used to get 10-12 yards of crushed asphalt for less than $3.00 a yard. If the approach is built correctly you should never have to renovate it, but every contractor is different. I can understand him using big rock if he can pack it in. I used 3/4'' crushed rock when i couldn't get the crushed asphalt, and i packed it in while the clay was still wet and that worked good too.
Once i used the crushed asphalt that was my preferred topping for certain projects. In spongey yards i would use 1 1/2''- 3'' rock to pack it down good and firm it up. That fixed the spongey spots but sometimes you had to do it for 1-3 years in a row to get it totally firmed up. By spongey i mean the frost boil spots that some yards get in the spring. Others might have different views on what works for them.
the recycle asphalt now runs 13 ish a ton so close to 20 dollars a yard. The state requires you to use 20% of it on jobs now so there is a pretty big demand. We mix ours with a class 5 to make it pack easier and little more affordable product. It is by far the best product for driveways and high use areas other than concrete or asphalt