I'm not saying there is tot enough achievements already, but I think it could follow the same logic as when killing monsters. Let me explain this further below:
After killing a monsters you get EXP, which then turns into level (after reaching certain amount of EXP). Now if you reach certain level , you will get some RP. Also after killing certain amount of monsters you will get some RP too.
Now while TS-ing , you will only get RP after reaching certain lvl. But not for gathering certain amount of resources. So in mining you'd get 10 RP after gaining first 100 iron.
I know it's probably not going to work because it may require to rewrite the way of storing the resource data, adding a separate counter to track all the gathered resources since beginning (So it would ensure that the counter will not be changed after selling resources etc.)
If you haven't noticed, there is already a total resources gathered leaderboard, so the data has already been stores. This idea is relatively similar to a TS attempts milestone which has already been thoroughly accepted(100% legit) by Stabzs. There is really no point for this.