I have no idea of cost, because I didn't buy one, but I did have a long chat with the owner of a large music shop (when he was not in sales mode) and I was assured that the electronic versions are now very capable of faithfully reproducing a piano-like feel and sound.
He suggested Yamaha to me - apparently they are the best brand in this sector by a country mile. Mind you I was enquiring in the context of getting in something on which the children could learn, so maybe there are high-end electronic keyboards that he simply didn't mention to me.
As it happens, my neighbour was getting rid of a 'cheap 2nd hand' one (free to take away) so I never got as far as trying out the electronic ones. Hope this is of some help.