regarding tsez: duly noted. and...bravo for the find. regarding compare/prepare: the OED vouches for cum/con "with" + par "equal" for *compare* and also has prae "before" + parare "prepare" for *prepare* (despite the etymological redundancy...for which see gems such as *aujourd'hui*). the OED also likens parare to parere "to bring forth" (whence "parent" from the active participle). it's possible the 2nd element in both words is entirely unrelated. this kind of thing happens.