Dear Umar,
C1 is a good choice, great location and well populated. C2 and C3 are also great location. C2 is mostly 1 Kanal with few 10 marla plots whereas C3 is mostly 10 marla. As per master plan, C2 has some disputed area as well. Another downside of C2 and C3 is high-tension electric line that runs between these two sectors and C, stay away from that as well.
Prices have slightly gone up in past few months, but not as much as in other projects. So there is still room for further price increase, do not expect price correction here. Bahria has been sitting idle in BE for too long, their slightest move will throw prices off the roof.
When you visit BE, also check out sector F, which is almost adjacent to C1, is on high ground with cutting land. The only downside is that its view will be blocked by high-rise commercials in front.
My advice would be, to visit the location, talk to few local dealers and then pick a possession plot only.
Warning Repeated: Only possession plot, no matter what sabz bagh dealer shows you.