I've been racing for ten years now and started following the trend "latest & greatest" soon after I started because everyone else was doing it, too. You know "big bores", "lightweight machined chassis" jada jada...
I've spend crazy amounts of money keeping up with it. But I still wasn't winning like I would have wanted.
Since then I've changed my strategy, a while ago (a year or so). It's really not a money issue, but parts access for older car models and engines is usually very good, if not better and the price is less, often even half less if you buy from eBay or local hobby shops, Internet etc.
I can tell my results have not gone worse. Not necessarily better, but I enjoy more since I spend less and it's not so serious anymore. I don't have learn the new stuff all the time and there's usually a lot of information available. Parts & models have been around for a while so they work and any issues have been fixed (Kyosho at least).
Just my thoughts.. newest is not always necessarily the best.. depends what level you're aiming at. At my level, it's not the tool - it's the skill that matters most, so I feel comfortable driving a car or motor/engine that has been around for a few years, even more. Usually those that actually have been around for a good time are very good, because otherwise they've died a long time ago.