Originally posted by DAP Long story short - the repair is going to cost more than the lens. If I were you I would try opening it up myself and fixing it. If the blades are oily take the glass out of the lens barrel and clean the blades with rosonol lighter fluid - clean up the gunk under the aperture ring while you have it apart. Draw a bunch of pictures during dissassembly so you will know how to put it back together.
May I suggest an upgrade to the above option. PHOTOGRAPH IT!
When I take things apart I find a sequential series of images better than anything I can draw... and I can draw.
You will be rewarded with a great little series of images and what you will have accomplished. If you screw it up you will have a great series to remind you how you screwed it up
Good luck, and keep us informed.