The slight detail you’re missing in the first argument is that you have to take into consideration the people who actually have breast cancer. Okay, donate could be the wrong word to use and sure, maybe people just want the skin regardless. However, be the person with breast cancer. Do you really care how the money for researching better treatment or an outright cure is obtained?
I have lung cancer; I could honestly care less about how a better treatment or cure was developed as long as it was developed because, you know, I kinda’ like living in a not-so-unpleasant manner.
Getting back to the subject, if the skin was made permanent, that plain and simply means a permanent source of funding for breast cancer research, as big or small as the amount of funding would be. Every penny helps, regardless of how it was obtained.