Somone wants to buy a Calorimetry from me, but since I’m not the designer, I can’t sell it. Right? Is there any way that I legally sell one? TIA
Ask the pattern writer. Her email link is at the bottom of the page on Knitty. She might say it’s ok. 
Personally, I would allow you to sell one… in fact I DO allow people to sell their finished knits from both my sock class and my free patterns. BUT, it’s up to the individual designer.
As far as copyright laws go if 5% of the design is changed it is no longer considered covered by copyright (this goes for art, not written copyright which is much much different) Heck, I can do 5% of unintentional changes just by the mistakes I don’t fix LOL!! But seriously, as others said, Just ask!
Well, I reduced the number of stitches by 16 because I changed the gauge. I wonder if that’s 5%? Thanks for the link, Silver. I will contact the designer.
I don’t think there is any hard and fast rule on changes by percentage. Good reading on the subject here: Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos and here: knitty.com
I would contact the designer.