Yes it is very important for a real estate agent to inside the property to get an accurate price opinion. I have worked the Wood Dale area for 20 years. I am sure we could work something out in regards to being able
to get into the house. I would be very happy to help you in this regard. You can never tell what a house looks
like on the inside, just by the appearance on the outside.
It depends on how accurate a value you want. A home in objectively excellent condition is worth more than one is fair or poor condition. One with many well done recent updates has more value than one where a homeowner tried to do updates, but they used cheap materials and look like they were done by a non-professional.
A drive by assessment can give a value range, but will be based on assumptions. A complete inspection will be far more valid, especially for an older house.
That allows them to see condition, decorating, feel the space, the floor plan. Those things make a difference.