Attending the event probably wouldn't be an issue because that itself wouldn't be a thing of value.
If this involves a real estate company that you are paying to sponsor so you can gain business then you have your Section 8 violation all written up right there. I would stay away from "sponsoring" a single real estate company.
On the other hand, if this is a real estate trade group or something along those lines and all agents from any company can attend and you are paying the same value that other vendors/sponsors are paying to have a booth then you are getting closer to something that could be permissible, but would need to be managed.
Opinions expressed are my own and do not reflect legal advice or the opinions of my employer.