I would also suggest that some of the bigger modding concerns would never charge for their mods.
I would have paid money for F1 91 or Enduracers or Proto C (when it eventually came out) for RF. DRM, GP79, and many others. But simply could either donate or pass on my thanks via forum or a modder who I knew helped out. That seemed to be enough
All these were mods that were worth paying for. For years Enduracers is all I played on RF and you think a tenner would more than cover that. OK not updated routinely, but once the basic bugs were ironed out they were fine, some had inherent issues such as default setups being way out on the odd car, but basically fine. All updates included.
But ONLY after I had tried it.
What is needed is for the BETA of a mod to be offered somewhere like here, for people to test, offer feedback, make suggestions. I do not use things like dash mods or display mods, but they could be offered for small micro transactions to make people download them without really worrying, and if they are good they will quickly make a few quid.
Then, something like an app store shop would be great. But you HAVE to be able to try before you buy. That is my biggest complaint with modern developers, it is all left to the Steam refund now for people to try games out. That is great, but companies should be more proactive rather than greedy with proper software releases. Demos.
Try before you buy would be my only stipulation, as some mods are really only suitable for certain driving styles or as part of a pack.
And that is how it works with apps, you try it, like or dislike and then choose to to grind or pay. That should be the model for PC based software too. Or mods for a game like this