Everything will be out of date if you wait long enough.....but is anything ever actually worth the increase in price? It's usually about desirability with the more desirable being newer.....so then that leads to affordability.
Facelift models generally offer a number of visual changes which improve on the original after the manufacturer has had a few years to think about it.
Perfect example and I owned both - Mk.3 Focus ST released in 2012 then the facelift in 2015. The latter is a far superior car and visually much more striking, so the only reason a buyer would choose the former today would be price.
The brand new Mk.4 Focus ST is certainly not the prettiest, so leaves plenty of scope for the facelift 3 years down the line. Cynics will say when a new model is launched the facelift is already pre planned.
To answer your question....the facelift S3 Saloon is the more desirable car, but only you can decide if the extra cost is justified.