Well whatever you do develop most likely I have more or less no say in it to some point.
There is already an export feature if you read the docs and it does work easily with a spreadsheet. I have even seen someone recently specify to use the custom delimiter of the & on google sheets. I don't know how things have been done in the past with that delimiter but you are limited because of how the Lua saved variables work. It has been done the same way since the beginning and I'm not willing to change that.
If you just want this for personal use I understand. It serves no useful purpose to know when something sold for x amount in Sept of 2022.
If for a mod then use LibHistorie directly that's what it's for. MM is not a library data receptacle for other mods to access.
If not for personal use then:
Warning: Spoiler
So what will I endorse? Nothing. I do not wish for MM data (Or LibHistoire) to be made public in any way. I think that about covers it but I'll elaborate.
I mean no making any software that will take the MM data from you and other people and merge their data together to have a better average price from more then just the 5 guilds you are in. ZOS does not allow any real time sharing anyway. TTC simply provides a pricing table in a very simple format that loads just like any other Lua file for a mod. So when you log in or reload your UI that file loads as part of the mod.
Why do people want to do this anyway? Do you people not understand statistics? You don't need the library of congress of data to make an average. The median and the mode are more important anyway then the outlier information. At least without writing a thesis about it. So having all the outlier information won't really help any.
I have mentioned this countless times. If I choose to do this myself some day in the future then I will do so. Do I have to explain why? NO! Mostly because I want full control of the development. Not that you do it in your spare time and I supervise. No, I mean I want to do it, period.
Right now even TTC has information that is false. I have reported once to the author of TTC and he was more then willing to remove the data if I could provide the information. I did but that was that one time. It happens all the time. People skew data all the time. People buy from multiple accounts they own to create sales data. They are so diligent at it that they do this over the course of 30, 60, or 90 days so that it defeats the outliers routine I have in place in MM.
Some people do not use ATT or MM and only use TTC. I don't go read reddit posts because I value my brain cells and my sanity but recently someone posted a comment to someone that they only cared about the TTC max value. That's just stupid. It is whatever some pleb put the item up for and he could have waited until the TTC exe transmitted it and then removed it from the guild store and did it again just to populate data.
There are obstacles in doing something like this that I have been brainstorming over for years and I do not want someone to make something that people get used to and then if I improve on the system start saying that the averages of my data are too low. That this other thing is accurate. You can see the irony in that right? People do that with the Bonanza price not knowing I trim outliers in a different way then other similar mods.
Nothing that you make will be more accurate. It will just be statistical data from the data pool you have. Your data, the TTC data, the ATT data, the MM data, the Bonanza data, none of it is wrong or inaccurate.
In fact Bonanza is part of what I have been brainstorming. It makes near MM or TTC averages from a small sample of data just from visiting a few traders in one city. I can expand that data pool by visiting other cities. With less then a few hundred data points I have the accurate average that the item sells for. Unless it sells 50 times over 398 days. Then no, because those are not items that sell frequently enough that you can track the trend.
I don't like the conglomerates for any kind of in game user experience at all. Not even selling crowns. That should be ZOS regulated not user regulated. I am aware that this happens with items as well not just crowns. Like some people buy up specific items as much as they can to control the price like De Beers® does with diamonds. For example this happens with Atherial Dust.
So I could keep whining about it and you could come back and tell me how you are very concerned and how you want to do something good for the community and you want to overcome all the obstacles so that everything is as honest as possible. Which is great and I appreciate that.
However, I have worked on BOSS, LOOT, Wrye Bash, TES5Edit, FO4Edit, SSEEdit, and several ESO mods since 2012. I even attempted to get TESVSnip to work and I repaired several mods that used it. The authors have since removed me from the credits even though I fixed their mods. Had I not people would have avoided them like the plague because of possible save game corruption from using TESVsnip.
Like I say what you chose to do I probably have no say in the matter. So it is what it is. However, as a courtesy and respect for what I have done for over a decade I would appreciate it if this is left up to me when I come up with whatever I choose to do for a global MM and Bonanza price. When I find time and resources to do so.