There is a substantial difference in price, although the mechanical Kinesis costs less than what I paid for the regular Kinesis several years ago (prices have come down quite a bit). More importantly, years ago when I tried the regular Kinesis the mushy keys were unacceptable. It takes a fair amount of time/practice to acclimate to a split keyboard and I wasn't willing to do that for a non-mechanical keyboard; the mechanical version removes that obstacle.