Yep, Waves has not made re-selling plugins easy. Sonnox too. It is not their business as they have sold their product to you and would very much like to sell their product to your friend/customer as well.
So it all comes down to what your friend/customer wants. If one simply wants to use the plugins, then it can be done as I stated before, but if one wants to see the licenses in one's own Waves account it's going to cost a lot. Probably more than either of you are willing to pay for.
So think twice; if you have two Waves accounts surely it is not optimal but if it works then hey...
