First, understand that tunings and repairs are not the same work. Replacing hammers, hammer surfaces, strings (or anything else) will not be needed as part of a tuning. An experienced and reputable piano tuner will do a quick inspection and explain, usually for free, if there are any repairs needed before a tuning can be accomplished. This is rare, unless the piano is very old or has suffered some type of water or smoke damage.
Second, piano tuning and a pitch raise are also not the same thing. A piano will begin to lose or drop pitch the longer it is out of tune. Once a piano begins to lose pitch, it will have to be brought back or “raised” before a tuning can be accomplished. This is more likely to happen over the colder winter months, which is why having a piano tuned as part of a household “spring cleaning” is recommended at minimum every year.
The cost of a good tuning will depend on the training and experience of the individual hired. Some technicians starting out will charge as little as $75 an hour for a basic tuning. They are looking to build their client base and encourage repeat customers along with good word-of-mouth advertising. Once that tech has enough experience and develops a more efficient work method, he will begin charging more. Most tunings will take around 1 hour to one-and-a-half.
Average cost in the U.S. is about $100 per hour. As with every specialty field however, there are individuals who stand out. For a very experienced tuner with a sterling reputation, $150 to even $200 an hour is not unheard of. Generally though, technicians that skilled are only called on when someone has a very expensive instrument such as a Nord Stage 2 SW73 or large Grand Piano.
Regardless of what type you personally own, annual tunings are necessary to maintain not just a good sound, but also to protect the investment you have made in purchasing a piano. This is not a sofa or a dining room table that goes out of style. A well-cared for piano survives generations and can be the centerpiece of family gatherings for many decades to come.