I've come to need a way of tracking and recording conversion rates of a fake currency on Roblox. I think javascript is suitable for the tracking part, however, I'd like to also record that data in a spreadsheet and create a refreshing graph as the data comes in. The resolution of the graph will be at most of 5 second intervals. If you take a look at the Roblox conversion page below, you can see the current positions made by other people to trade their robux or tix to robux or tix. The page displays the top trading positions made by others. I only want to track the conversion rates at the top of each column as shown on the trade currency page.
If I were to create a program locally stored on my computer, what language(s)/program(s) should I use to accomplish this? Also, if I were to host a server (Using my raspberry pi or free hosting service), what language(s)/script(s) should I use to accomplish this? Lastly, if I were to make this an online thing (With my R-Pi or free hosting), I would like to access the graph through a browser, either on my network or on the internet (Which I've done before when creating a website for my R-Pi).
Thank you for your time in reading, Cameron
Link to the conversion rate page
EDIT: I now know you can't see the trade currency page without logging in with an account (Which is free). You can see an image here and a wiki page here. I've decided to use Bubby4j's answer which supplied me with a helpful system that already did what I asked for. I now only need to fix it (As it may be outdated) and get it running on a server.