That happens - don't sweat it. Radiator guards are priceless
Here is what I would do - take from it what you want.
I would run some strong wire through the radiator in that damaged / pushed in area and use the wire to carefully pull out the dented section. Slow but sure and you can probably get that back to a pretty decent shape. May take some engineering to get the leverage needed to pull it out but where there is a will there is a way. I would not buy a new one unless that one is leaking and not repairable. There is such a insignificant change in the cooling from that dented area that I doubt it could be measured.
Then I would mount some radiator guards and get back to riding.