The first three "Pot Thief" mysteries by J. Michael Orenduff are available in a single volume -- The Pot Thief Mysteries Volume One -- and on sale at Amazon right now. I bought this last night for $3.99 -- today it's showing for me at $3.03. This is a very good price since the books are available individually at $8.99 each.
The three stories are The Pot Thief Who Studied Pythagoras, The Pot Thief Who Studied Ptolemy, and The Pot Thief Who Studied Einstein.
These stories are published by Open Road Media, and they tend to change their prices quickly, so I don't know how long this offer will last.
https://www.amazon.com/Pot-Thief-Mys...dp/B072542KKF/