More (probably dumb) questions from a potential first time home buyer.

Hello everyone! I had a couple of questions I was hoping you guys would be able to help me out with. The first is regarding the use of a realtor. I have a contact that I work with on unrelated business that is also a very well known and respected realtor. I have mentioned the place I am looking into buying to him and he was, of course, willing to work with me on it. However I recently went to check out the place, and the seller made a point to tell me that there was no need to use an agent because they can draw up contracts at her office. This struck me as a little shady, but at the same time, I know nothing about this process so I figured I would run it by you guys. I do want to have a realtor on this, right? It wouldn't affect me in any way. I would still pay the advertised (133.5k) rate, and would have assurance that it was done right. Please let me know if there is something that I'm not accounting for.

My second question is regarding home insurance. I'm somewhat confused because of some of the online calculators I have been using to estimate a monthly payment. For example, realtor.com estimates that monthly home insurance would be about 35 dollars. But according to google, the average tends to be more than double that (75-100). Is there something that I am missing in this regard? That is quite a large disparity, and I'd really like to have a good idea of what my total payments are going to be before diving into this process.