I am pursuing M.Sc. in Physics from a good college in India. I screwed up my first few semesters (got two backlogs in chemistry and sociology


I have been active in research and planning to apply in the related area. I have submitted a research paper in Euro. Phys. Let. as a first author. Presently, I am working on a Phy. Rev. Lett (1st author). I am also expecting good reco. letter from my co-author professors.
I am under a dilemma, I have heard that grades matter quite a lot in US PhD programs. Since, my grades are mediocre, should i apply to US Ph.d program, or will it be a waste of money (assuming that i get the papers)?
My decision of taking PGRE, GRE and TOEFL is also hinging on it.
TIA.