Bethesda has confirmed that there's currently no plans to bring paid-for mods to Fallout 4 when it launches later this year.
The studio collaborated with Valve in recent weeks and botched an attempt to build a marketplace around paid mods for Skyrim on PC, and it seems they've learnt from their lesson.
Game director Todd Howard said this to Spiegel (as translated by our colleagues over at Gamereactor Germany): "How long was the system for paid mods online? 24 hours? I can only speak for the current moment, but there currently no plans for a pay-system."
There was widespread criticism of the way that paid-for mods were introduced, and while it's not certain that they'll never appear for Fallout 4, it's not looking like they will at the moment.
With the studio confirming that mods are also heading to Xbox One and probably PS4 too, we're not expecting the studio to start charging anytime soon.