The cost of a furniture assembly service in Potomac depends mainly on the kind of furniture that has to be assembled and its size. It has been reported that a quality Potomac furniture assembly service can go as low as $80 and as high as $180 with an average cost of $120. An average bed can be assembled for $90 while a more difficult bunk bed may cost you $125 or more. Dressers and nightstands have varying assembly prices depending on the size. Free standing closets can be assembled for $120 to $150 depending on the number of racks and cabinets that they have. Nightstands and bureaus can cost around $70 to $150 to be assembled.