Most developers do underestimate assessments, sometimes by alot. It is in their best interest afterall they are trying to sell condominiums (in a hard market nonetheless!). Alot of management companies will reduce their fees during a condo renovation for the developer as well. you will usually find that a management company will charge per unit. The cost doesnt change based on unit size. This is just a way for them to markey themselves. Expect to pay around $35 per unit per month for an established company. Be careful of newly formed or small companies that may undercut, as they usually won't have the relationships with contractors, municipal contacts, or experienced personnel. Also, if they have been around for a while you know there arent any problems with embezzlement or dishonesty, very important! For the most part, if they are doign a good job and are familiar with the building leave sleeping dogs lie. Transferring management companies is not a simple task and you may end up appreciating what you had unless they are really bad.