Scott you make some good points...... however there is a fine distinction between a pro offering help and advice whether paid or unpaid and the same pro charging for a cowrite.
As Brian said so powerfully nothing wrong with a cowrite as long as there is mutual respect and the same skin in the game....IMO charging for a cowrite is just prostitution in its worst form....and there is no reason to do so except to make a financial killing.
Would I pay for a cowrite?......never
would I charge for a cowrite?....never