I don't know if you have any game fairs in your area coming up, but I got the cheapest price for mine at a dmt knife sharpening stall. I've been to a few, and it always seems to be there..you could check I suppose. I had to order mine there and they sent it to me, was about £20 cheaper.
Waht are you hoping to do with the course? I was disapointed with mine. Perfect for keeping my waterstones flat, but not nearly as course as I had hoped. The Extra course is the one to get if you want to use it for flattening backs of irons etc.
Shrubby i think thats the old style one with the holes? Im looking at the continious stone, i am worried it may liek you say develop a bald spot. I bought some cheap ones and they were rubbish but i think DMT are alot better. as ever you get what you pay for.