Main advantage to Ballistic Tips (as well as other polymer tipped projectiles) is consistent ballistic coefficient. The tips don't get battered in the magazine by recoil, so each bullet is pretty much the same length as the one before it. That and the long streamlined shape help ensure more consistent performance at long range. The tips can also aid in initializing expansion. FWIW, the Noslers do seen to be one of the more accurate bullets available that are also suitable for hunting.
For economy, I would consider good old Remington Core Lokts. They're fairly inexpensive, perform great at 308 velocities, and can produce some surprisingly small groups when a good load is found. They may not shoot as well at 600+ yards as the polymer tipped slugs, but inside that they should work quite well.
Hollow points tend to be good at long range as far as grouping. Most BTHPs are match bullets, but a couple companies offer this design in a hunting bullet...Sierra and Berger immediately come to mind. (Yes, Barnes are BTHP, but from personal experience expansion at long range from a 308 can be iffy, so I don't personally recommend them.) I have not shot the Berger or Sierra hunting BTHPs on game, however, so I don't know how well they perform at longer range.