As rare as hens teeth

I've 2 phrases that that I'm curious about in regards to use and origin

Rare as hens teeth... and... For love nor money. Any ideas?

scarcer than hen's teeth -- Hen's don't have teeth. One reference says it is an Americanism that probably goes back to colonial days but was first recorded in 1862. Encyclopedia of Word and Phrase Origins by Robert Hendrickson (Facts on File, New York, 1997). Page 595.

I couldn't find an origin for the second. But it is used like this: I wouldn't do that for love nor money. Tickets aren't available for love nor money.

"Love" has had the sense of "non-monetary motive for doing something" since at least the 16th century - the King James Bible is the origin of the phrase "a labour of love" (I Thess. 1.3). People have been playing games "for love", meaning "for no stakes or prizes" since at least 1678. So at any time in the last three centuries, if you wanted to say that you couldn't get something (or wouldn't do something) either as a favour or for material inducement, "for love or money" was a concise and clear way of putting it. (VSD)