Couple of years ago when I checked about medical colleges in UK, their tuition fee alone was more than 26k pounds a year and yes no scholarships/bursaries etc. For US, you have to do a 4 years bachelors degree in some field before you can start doing 4 years MD(so, its atleast 8 years till you get MD in US) and tuition fees were around 50k+ $/year and no scholarships etc(most students take loans but they are available only to US nationals). If I remember correctly, for UK, you had to give their MCAT and apply through UCAS and for US, after your bachelors, you had you give their MCAT and apply according every school.+ IELTS(or C in english at o-levels) or TOEFL for UK/US respectively. No other special licensing tests were required at this stage but only after you complete your medical degree and then were looking for a residency.
So, it really is much expensive to study medicine abroad. However if you want, you can go abroad after completing MBBS here. And to my knowledge, AKU, karachi and then Shifa, Islamabad would make it easiest for you to do so. KEMU, Lahore is also good if you want to go abroad and you can get admission there now with 90% marks for an A*. I mentioned these colleges because there is trend among their students to go abroad(more often if not always, the US). In other colleges like AIMC, SIMS, NMC, etc among govt. medical colleges and LMDC, CMH, FMH etc among private, there is not much trend among the students to go abroad(although there will be a few every year but not much) and as such you'll have to be proactive or you won't even know how you can get residency abroad before its too late. But its just as much possible to go abroad, so it all depends if you are willing to work hard.
Btw about medicine(as it is for just about every profession), you just have to reach for perfection in your knowledge and skill not worry about money, it'll come to you itself.