Looks like you can buy directly from University optics
http://www.universityoptics.com/order.htm
Some prices converted to AU roughly without shipping
MK80 32mm 82 degree =$391
32mm 60 degree = $184
40mmMk80 70 degree=$298
25mm MK80 =$259
The 40mm Mk70 one I have I like but it does require spot on eye placement because of kidney beaning which may put a lot of people off , but with a little care its very nice
Good luck keep an eye on Astromart too