I don't know why you want a Switch but I hope that you know precisely what you are going to get with it. Better lower your expectations, on a technical point of view. For the same price, Series S is a million time better, unless you are planning to play handheld. In this case, a Switch Lite is much better suited, even though ambitious games still look and run like poop on it (that's the same on OLED/normal Switch of course). Smaller screen helps mitigating the issue, but does not miracles.
If you already have a Switch, upgrading is utterly pointless. Just my two cents.