I know that might sound crazy, but lets be honest, many, many of us will buy an external amp. I'd like to spend less and not have an internal amp/only a line out. Any of the rest of you? I'd be interested in one... 
 
(It's not like most of us don't have a phone, an old shuffle, or maybe even a Clip+ if we ran out of battery to our external amp.) 

This is not such a crazy idea. I remember this being suggested a few times on the Fiio X7 thread. This configuration may also suit people who are not so interested in portability. A good interface coupled with a quality DAC and quality OPamp with optical/lineout would make a good source. As far as I know nobody has produced such a device, probably because there is only a small market for it. Obviously if you put in high grade components and charge the same as a comparable media player with an amplifier people will think it a con especially these days with microsd storage also being an extra cost. I would be interested in such a device for home use preferably with circuitry to bypass battery charging and high on board storage but I'm not holding my breath.

I for one wish there was a DAP such as this or at least knowing for sure that a line out is not touched by the amp part of it.  I drool over the RWAK100/120-S mods.

You can't get rid of the dac in a 3.5mm out setup, and installing a cheap internal amp circuit costs in the order of 10 cents, you're not going to get much of a saving from that, may as well have a cheap one. To reduce noise, you really want to use the usb out into the amp with dac.