You will probably be very dissapointed if you think that just by switching the frame you are going to get to 14.25 pounds. It's going to be very hard to do with the clinchers.
If I misunderstood then I apologize. However, getting to 14.25 pounds is not easy or cheap (trust me).
As for being worth it, if you can drop over three pounds for $300 then I say yes, it is definitely worth it.
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I may be fat but I'm slow enough to make up for it.