I just put a set of 30 mm rise on my night hawk. They are 7/8 bars and came from highdesertmotorsports541 on ebay for $22. What you have been quoted seems about 2x higher than they should be through MOST sources. If you are trying to get more than 2 inches of rise maybe you should consider some different bars. just to get an idea look at jpcycles. Most risers I found in my search were very expensive and not nearly worth their price to me.
1984 Honda Magna 700, 1987 CBR1000F, 1991 Nighthawk 750, 1994 FZR600, and for the dirt 1995 KTM 300 EXC and finally a 1986 KX500