International student here, luckily got into some top-10 programs this cycle. From a non-English speaking country.
My two cents for international students who want to get into top PhD programs in the US but lacking the financial resources to invest in a foreign MA:
1) Go heavy on stats, math, econ, and programming. Do some graduate-level statistics/econometrics and calc 2. Take a few courses that require using Stata, R, Python etc. If you don't have recommenders with good connections in the US to credibly bat for your research potential, taking quantitative courses is a much easier path to signal your skill sets.
2) If there are such opportunities in your school, do a study abroad program (exchange student program). Pick an R1 university in the US (even better, a school you want to get into in the future). Work exceptionally hard in all courses, develop good relationships with professors, and do some research projects there if possible. Ask for recommendations from these professors after the semester. Most R1 professors graduate from top programs, and I assume they have better connections with committees of the programs you are aiming for. Their recommendations help demonstrate your English ability and compare your academic achievement with other students in the US. Admissions committees will get a better sense of what kind of student you are.
3) Be really careful when drafting research plan in your SoP. Read political science journals widely, especially APSR, AJPS, and JOP. What topics are people working on? Which methods do they use? Topics (and methods) the mainstream US scholars care about nowadays may be very different from the paradigm in your home country. Definitely don't write on a topic you are completely unexcited about, but you are going to be expected to do this kind of research when you start graduate school. If this is not for you, a PhD in the US might not be a good idea.
On top of everything, keep in mind that the admission process is a signaling game. We all need credible proofs for our abilities (and fitness with the program).
I got a lot of helpful advice from this forum, so I really hope my experience can help!