One guy was selling one of these here for 30k, I was interested, but its top speed was 20 kmph maybe due to lack of gears. I clocked myself on my man powered mountain bike and found out that 35kmph is more like the speed on level ground which I would be looking for. The point is you do not want to be too slow on roads with only two lanes or something like the Islamabad highway and that has an incline as well.
I think 40k for a full bike or 10 to 15k for conversion kits is a good price.