Let's start with the benefits of purchasing a new piano from a dealer.
Firstly, all new pianos come with a warranty. Yamaha's for example is 10 years, and Hailun's is 15 years. It is very nice to have somebody to phone and take care of any problems that arise.
Second, new pianos all come with a complimentary tuning and delivery!
Most dealers also stock some used inventory. A good dealer like Don's piano in St. Albert, will completely go over the piano and regulate it before the sale. This kind of service means that you will pay slightly more than for a piano purchased off of Kijij. Most dealers will provide a warranty on used pianos and this can be open to negotiation.
Most dealers will accept trade-ins or at the very least will haul away your old piano for free when the new one is delivered.
The drawbacks to purchasing from piano dealers are as follows:
Salespeople will tell you anything they can to encourage a sale. This includes "white lies".
Salespeople will trash talk any brands that other dealers are carrying.
They will discourage purchases from private sellers.
Salespeople can make any piano sound good.
Because piano salespeople can make any piano sound good, it becomes VERY important for YOU to play the instrument for yourself. Don't take their word for it, and don't be shy. Even if you don't play very well, at least play every note from bottom to top, one at a time. Do this slowly. Make sure the notes sustain long enough with good clear tone. Do this test both at a medium volume and a very soft volume. Playing the piano softly will give you a good idea as to how well regulated the piano is! If all the notes play very consistently at soft volume levels, the piano is probably in pretty good shape.
1. Giovanni Music - Dealers of Yamaha
The Edmonton Piano Tuner