Most of these questions will be answered when I decide to fully launch the pricelist feature of my site, which is likely still a couple weeks out at least. Many features of the service are still incomplete. But given I did open this up to the public for beta testing and questions, I'll answer regarding how things are setup currently:
If the buying list basically what you're willing to pay for items or is that the prices that your system searches for/highlights when I'm searching for certain items to buy?
That is the price that you are willing to pay for that particular item or property, or what you're willing to accept for that service.
I also noticed the trade button, I'm flying so I haven't experimented yet, but when you click trade does it setup a trade with the items you want to buy or sell (based off of the "pricelist" like TornExchange)?
This will simply open you to the page to initiate a trade with the user whose pricelist you are clicking that from, nothing more.
I like the way you've setup your system better than TE so, the more I can learn about how to use it efficiently.. the more I'll use it.
Good news here, is that I do consider Ata (the creator of TE) a friend of mine, so the good news is that I plan for users to be able to use both interchangeably. Of course, there will be some healthy competition between us for the sake of improving upon both services.
Do the "Market Filter" and the "Market Resale Helper" work on your site and if so I don't see them active in Tampermonkey.
I'm not sure what scripts you're referring to. As far as userscripts go, I don't make any for my site since anything I want added I can just add to the site itself (and I've taken inspiration from userscripts others have created for my site to integrate their features into my site).
Most market fillers/helpers that do run on Torn do use my site to some extent though via the public API provided through my site that you can find here!