Wow, how about a little punctuation?
Without a photo or two, I couldn't make a very educated guess about value.
I have a custom .257 AI in a Mexican Mauser action with a 23-inch Krieger barrel. I get around 3,050 fps with 115 BTs and Partitions. I see about 3,200 fps with 100 BTs and Partitions. It does the job on Coues whitetails and desert mule deer with the 115 grain bullets. However, I have taken more pronghorns with it than anything else, using either of the 100 grain bullets.