new cable service charge for running new wire

i recently completed a new build house in a very established neighborhood with customers on either side. 2 weeks ago xfinity told me the closest connection point was 540' away and it would cost $3300 just to get internet service to my house. i was shocked and asked if they could research that more as i know the neighbors have xfinity. Yesterday they sent someone else back out and they are saying i have to pay $4,500. anyone else have this issue, how could the price jump $1200 in 2 weeks that gives me no faith in any of the estimates? does this sound right