Hello,
I suggest that you apply for OINP, this is your safest bet, althought the CRS score might reach 450 but i think this is a long shot. but come on what is 1500$ compared to a life changing decision?
What i idealy suggest is that you resit for the IELTS Exam, and you might get a better score and go above 450, if you did get a better score then you can withdraw from the OINP, they will not cash your cheque instantly.
I hope this was helpful