INSEAD is definitely the school to go, especially if you are not completely focused on France. In Europe there are two top choices - fully acknowledged by most of the recruiters/HR - INSEAD and LBS. LBS is usually considered for finance and INSEAD for consulting and corporate - thus, it would also perfectly suit your interest in corporate post-MBA positions. In France, though, also HEC provides you with great job offers. Outside of France INSEAD is much stronger.
Nevertheless, I would definitely go with INSEAD - it will for sure pay off in a couple of years. With January intake option you even have the chance for an internship during summer - which could help you in any direction.
Think of 33.000 € vs the rest of your life (at least working life). I would ask HEC for an extension of the decision deadline - they for sure will agree on that. And then the 25.000 € difference is def. worth it. Then use the four months by conducting some travels, pre-MBA internship, or preparation.
For me the choice would be clear - I hope it helps.