Javier
It the property is listed by a Realtor, that tells you, the consumer, that the cost of representation is being paid by the lender.

So I would find a very sharp Realtor to represent your interests. They are working for "free" from your standpoint, their fee paying paid by the lender.

Plus, you are not going to want to pay more than the property is worth, right? So you need to know that market value. A sharp Realtor will analyze the property's market value so you can determine how much you are willing to offer.