@drtroubles - Rhodium is actually a precious metal too, and is much more costly than gold. You don't have to worry about rhodium plating wrecking the value of a ring, all it really does it make it brighter and whiter. The rhodium plating does a great job of add lustre to the white gold and making it more attractive.
Generally you should thank your stars that you have had your jewellery plated with rhodium, but if you really want to go completely natural you can just ask for a ring without plating. I am afraid you might find it disappointing though because white gold without rhodium plating has a much duller and darker finish.