Facebook Marketplace Web Scraping and TOS

I am making a web scraper for Facebook Marketplace posts which I plan to rent out to people in the flipping community, I've noticed that the legality is somewhat in a grey area. It seems to be fine except web scraping is not allowed according to Facebook's TOS. It feels like this would probably be more about guarding the personal information of its users which I am not using at all.

I'm curious if anyone knows how likely it is that Facebook could take some legal action or if there is anything I can do to protect myself against it.

Yes, Facebook is known to take legal action. Mainly regarding providing/advertising services/tools on web-scraping, not on the web-scraping itself.
Overall, the most important questions would be: Do you need to explicitly agree to the TOS to get access to the data you are scraping? If so, you need to follow the TOS. If not, it might be more challenging for the TOS to be enforced, but that doesn't mean they won't try.

Here is an excellent presentation in regard to the legality of web scraping:
Also, an article/statement posted by Meta itself: https://about.fb.com/news/2020/10/taking-legal-action-against-data-scraping/
Brightdata being sued: https://www.theregister.com/2023/02/02/meta_web_scraping/ (Fun fact: Facebook/Meta was a customer of Brightdata, indirectly or not)