E1 costs hovers around $180-$500, but more realistically around the $200-$250 mark. Worldcall's E1 rate is US$ 240/Mbps. Others are usually much more accommodating.
E3 - No idea as to what that is going for these days.
STM-1 has come down to the $18,000-$20,000 range now. Depending how on how well you talk/convince others, you can buy transit as low as $ 12,000 even.
PTCL's Internet Bandwidth monopoly ended quite a few years ago, when essentially TWA went into operations. Bandwidth prices will continually keep coming down, the question is - about how Service Providers will continue to make money of it - just as bandwidth prices decreases, so does the accumulated revenue figures for ISPs (not always in proportional to costs).