Don't ask anyone how long THEY would take for YOUR pricing.
If everyone says 1 hour and you price it so, but takes you four hours, you are getting burnt.
Price it according to how long YOU think it will take YOU to do. If you say 2 hours and it takes four, then so be it. Vice versa as well.
Take the cost of materials, overheads etc and add your desired profit and live with the time factor - either over or under the time allocated. Either way you still make the $$$ amount you desired from the outset. Also consider that if you determine a $100 profit, don't look at it as $100, look at it as a $100 discount on your electricity bill.
Cheers - G