Just learned that I could transfer the week into the account of the person if she/he is also a member of RCI. There is a fee to do this but then you could do your own search and not have to pay for a guest certificate. So, cover the transfer costs and add a bit and you've got yourself a good price for a week somewhere. I am not sure of how to do this but if anyone is interested to buy the week then I'll find out.
Cheers.