Replacing W/D and H/W Heater

Hi,

We have a pretty old W/D combined unit and H/W heater that need replacing. W/D on the top floor of our duplex and heater is in the basement.

Looking on Lowes, Home Depot etc. these guys all sell the appliances and will apparently do the services included with the price.

Couple of questions…is it advisable to use their services? If not, any idea how much it would cost to hire somebody to do the necessary installation work?

Thanks!