My personal opinion is that if you have a part in catia format and you want this part in ProE format, the only solution is to find time to re-design it.
I don' t think it is a good idea to buy a translator to make this job for the following reasons :
1. You must re-check the part or assembly to see if the features, relations, mating relations, equations, e.t.c. issues to the transfered part or assembly,
2. You must keep your translator updated because as you know, both Dassult and PTC updated their programms every 6-8 months.
3. I don't think that every translator can carry the design efficient of the part or assemlby to the other program.
My proposal is to find a way to transfer your part or assembly as bode feature to your desired program (by iges, Catia Direct, e.t.c.), study it in the Pro/DETAIL module and rebuild it again, so you can keep your design intent high and efficient.
Thanks for your time
Karavasilis Christos