Okay, so I had last driven the F14T a while back. Probably 2015.
I'd upgraded to PR123, all save the last three engine upgrades and completed the series 100%. Two of the last engine upgrades are gold. 250 GC for stage 6 and 565 GC for Stage 8. Those were the days they'd allow you to complete 100% without cutting your throat.
Anyway now there's a 30% discount. As far as I can see, the Ferrari is only in Campionato Scuderia Ferrari and the exclusive series. They added a lot of good races for the Campionato campaign while I was gone, such as a 10 lapper at Red Bull Ring, an 8 lapper at Silverstone and at COTA. Which I can now do still with the PR 123. Im not a fan of the exclusive series anyway, because there's plenty of good racing in the regular series. So don't think the upgrades are worth it.
RR3 fandom mentions a "Ferrari Evolution" bonus series but I can't find it on my Legend tab. Anyone know how to locate that and what the max PR is? And should I just leave it at PR 123?
Edit: Found the Ferrari Evolution series. Yep completed that too at PR 123. So for me upgrades not needed.