Not difficult, but not trivial. To do it right, you'd need a new table, a cron job, and ideally an ACP interface. If it was just a quick hack of the base code with hardcoded values, a skilled programmer could do it in a half day with a minimal level of testing. To make it an extension and test it thoroughly, that's at least 2-3x more work.
By the way, your offer would be equivalent to asking a skilled mechanic if he'd replace your car's leaking head gasket for 20 euros. Sure, it's not difficult, but it takes time and skill. At least in the US, my preferred mechanic wouldn't even agreed to put my car on a lift and inspect it for that pay.
And before anyone asks, no, I
absolutely am not interested in coding opportunities.