Hhmmm now ive been watching the Porsche market for 12 months , namely the 997 , 981Cayman & 991 .
The 991 seems to have dropped pretty drastically the last 6 months though i think has bottomed out early £40s (eg https://www.pistonheads.com/classifieds/used-cars/porsche/911-carrera-991/porsche-911-991-carrera-2-pdk-2012/10139905)
propped up by the later 997 gen2 still seen at high £30s
Porsche 911s of all years have often followed a fall - level - rise repeat sequence over periods of 10-15 yrs so wouldn't surprise me if the 991 went upwards again from this point , there was a well specced black 1 owner 30k carrera 2 991 privately advertised on PH at £41500 the past few weeks , gone now no doubt bought for £40k , i can see that car in 12 months with another few thousand miles being seen good value at £45k ?
All speculation of course

981 Cayman next for me but i can see the 991 being a target car in the not too distant future