Yeah I did a little searching at ACC4Less and it seems it's not very common- might be mostly a Denon thing (surprised Marantz wouldn't follow suit). It starts as low as the x2600h:
Supports Dolby Atmos, Dolby Atmos Height Virtualization Technology, DTS:X, and DTS Virtual:X: Enjoy an immersive, three-dimensional audio experience up to 7.2.4 with an additional 2ch amplifier.
It seems they want to sell us more expensive AVR's (imagine that) to go from 2 to 4 heights. It's quite a jump for just those 2 extra speakers- because you're not just paying for 2 extra amplifiers, but all the added power and features of higher end kit. The pre-outs would seem like a great solution, since I imagine most of us into Atmos probably have an old piece lying around we could get 2 channels from.
Denon makes the zone 2 pre-outs on those assignable- which doesn't seem like it would be that hard to do. Funny but some of the mid-range 7.2's have pre-outs for the fronts, but they aren't assignable. Some even have pre-outs for all 7 channels, but none for the extra 2 heights. They just seemed designed to get more of our money as opposed to efficient, well-engineered rigs.
Supports Dolby Atmos, Dolby Atmos Height Virtualization Technology, DTS:X, and DTS Virtual:X: Enjoy an immersive, three-dimensional audio experience up to 7.2.4 with an additional 2ch amplifier.
It seems they want to sell us more expensive AVR's (imagine that) to go from 2 to 4 heights. It's quite a jump for just those 2 extra speakers- because you're not just paying for 2 extra amplifiers, but all the added power and features of higher end kit. The pre-outs would seem like a great solution, since I imagine most of us into Atmos probably have an old piece lying around we could get 2 channels from.
Denon makes the zone 2 pre-outs on those assignable- which doesn't seem like it would be that hard to do. Funny but some of the mid-range 7.2's have pre-outs for the fronts, but they aren't assignable. Some even have pre-outs for all 7 channels, but none for the extra 2 heights. They just seemed designed to get more of our money as opposed to efficient, well-engineered rigs.