plenty
there are 2 .243s in 788 at the local gun shop for $470 each in good shape
want ad, gun show, gun shop
In a Gun Shop
50-200
gun shop, gun show, want ad
100-1000 USD or so
788's are about as rear as hens teeth. they were made in the 60's. just keep looking good luck. try gun shows
Blue Book of Gun Values
Gun Parts Corp or Jack First websites
See: http://www.gun-data.com/tour7.html this may help you.
20-60 USD or so