My suggestion is to have your agent do a full (CMA) report on the property so you can see what they have been selling for and the history of what they used to sell for , how long it has been on the market along with considering the current conditon etc. There are many things that you look at when coming up with the value of a property and its potential growth in your investment. This protects you from paying too much and/or getting surprises later when in the middle of a transaction.
This will help you determine a price that makes sense. The beautiful thing about being the buyer is that the service of a professional Realtor is of no cost to you and is one of the best ways of getting an idea of the value of the home and its history. If you don't have a Realtor I honestly think that should be your first step. I promise you, its not just because thats what I do for a living but its the best way of protecting yourself. Think of it as if you were going to court you would want someone who knows the law to represent you, so you hire a lawyer. We are specialists in Real Estate so we are educated in protecting people in the purchase or sale of their home.