If the goal is to get an idea of what a player is worth “at this moment”, this is similar to the purpose of the first-year league filter on the average values page. That filter becomes less useful after auction drafts are over.
I think adding a rolling average of the last 10 adds would do a good job of quickly showing what a player is going for across the Ottoneu universe right now. That could be a low-impact quick addition to the player page.
A list of all transactions across all leagues that is searchable would be quite large and resource-intensive. If the value-add is understanding what a player is going for, a rolling average is a much easier way of indicating that.
I’m open to the idea that the rolling average should be over X days instead of X transactions.
For trades, there is a live trade feed thread that can be searched.