It’s possible if you have the proper API endpoints. Rolimon’s has an API to do this if you don’t have a proxy to your disposition.
If you do have a proxy and want to create your own integration, you can do so with these endpoints:
https://catalog.roblox.com/docs#!/v1
For the part about live or nearly live updating, I don’t think there are any ways to get a signal when the page updates so you are going to have to check the price every so often, like every 30 seconds or so. 2 times a minute is not going to make you hit any limits so you should be okay in that regard, however if you’re creating hundreds or even thousands of requests a minute, there’s a good chance you’ll reach the limit, however so do be cautious while implementing it and use your budget wisely. If you hit your budget limit, it can and definitely will error because Roblox tends to go down and their APIs do fail from time to time, so be sure to implement pcalls and whatnot to ensure your whole system doesn’t mess up when it inevitably does fail.
As for visualizing it, I assume you want a line graph like so:
If so, you can implement your own method using atan2 for creating one point to look at the next, there are many posts on that. If you are okay with using open-sourced modules, though, you can use #resources:community-resources, I’d probably use the one by boatbomber which you can use here:
Let me know if you need additional help, I’m not the best with math but I’m more savvy when it comes to working with API endpoints and data but I’ll do my best to help.