I had them on a bike I bought briefly, didn't ride it enough so have no opinion. Shinko do make a decent, well regarded line of racing tyres.
 If you want affordable and long lasting, try Cheng Shin. I had a Barracuda on the front of my bike for over two years and it was a trooper, great traction, great wear and a very, very good price. You won't find a matching rear though, so consider that. Not that I noticed any issues running it with both a D205 and OEM rear tyre.
 Another good budget brand I hear a lot of praise for are Maxxis.
 Oh and cost differentials are usually due to companies having to pay huge advertising budgets and greedy reps....

 Regards, Andrew.

 Vstrom is gone, on the hunt for a GTR.