For me, I would say that if you feel you're selling your soul - you ain't really moving away from pure idealism as a reality , more of as a 'project'.
I know what you mean- it wasn't an 'all in' shift of perspective for, but more of a 'slipping into deep waters from the shallow end' that took a few years of adjusting to the temperatures of the waters.

The thing I found, was that once you went in, (and didn't 'play' at it), you found that getting deeper didn't bother half as much as you thought it would, and  my soul was no only still intact - but healthier for the experience.

Never sell your soul. 
(maybe accept that it's not as precious as you once thought? I dunno -I totally made that up on the fly).

My bill is in the post. lol