The SR 400 yam was an ok seller for yamaha a few years ago too, there is as market for such a bike, and with enfield going all OHC and Leaving the Push rod even the 500 model drift off in history, Their Value though strong at the price point in some areas of the world might not remain so long term.
the better performing Liquid cooled 450 hymalayan by example being less well acepted in the enfield world in the UK than i hear The UK importers expected. The clasic 350 sales and hunter model are atracting popularity from t5he enfield faithful, the resale value failing is of concern to new buyers but good for those looking for used examples after others take the hit for them.
Not sure the Bullet 500 is still made or will reapear. but its sad the OHV went from the RE Line up in the UK .
Sometimes if its working just roll with it this endless persuit of performance in motorcycling might be counter productive in many buyrs requirements or needs, typical RE buyers might / most probably are not looking for the latest and greatest mearly hankering after a nostalgia boost is aq bike that worked aceptably in history and today why this endless change ? It adds weight complexity and Expense all killers of the old type bike enthusiasts that tend to play a large part of the RE fanbase now and historicaly.
Look at the interceptor 650 its slower heavier slightly smaller than the 1970 Intercepter 750 i had when i was 18 in 1976 , and dont get me wrong i like the new 650 intercepter but if it was as light as the 1970 version i would like it even more. Bikes and cars and i supose4 people get fatter as they get older it seems look at the real MINI and the Melenial BMW Mini for example its huge compared to a real mini. If its not broke dont fix it Retro needs to be size and weight too not just a name or essence of style in the consept then Retro bikes would be posibly taken seriously by more not just apreciated as a design exersise that is Quaint.