@aqibabas brother actually i phone 3g is now selling for cheap but in that price you can get many cellphones having more functionality but iphone 3g has edge over others in terms of apps specialy and camera is awein in it but kaam chal jata hai and battery too and apple didnt left iphone 3g for the updates ( firmwares ) till 2011 so u can enjoy new firmwares and option in it if you get factory unlock and if u get software one so i think unlocking is the main problem
as far as htc is concerned it is a good phone but it came for the lower midrange and it lags too andriod is open OS u can do many things but in terms of quality apps iphone wins the race
and remember iphone 3g came as a premium device not the midrange like htc