Against all the feelings of refusal inside of me, I have to agree with Azhelika on this.
I'm not sure how well this works in japan - they seem to be more social in general - but the trade evolutions are doomed to fail in the western culture. I used to trade between two Transfer Paks, but this isn't an option of course ( ´,_ゝ`)
So yeah, I really like the idea. The evolution fee could also be pretty heavy, like 100.000 or something like that. That way people will think twice if they actually make them, and we even get a decent money sink something to use our Pokédollar on <3
So yeah I really support this idea. Make this an alternative with some heavy downside.