Is there a specific reason you want the new version of the mini-lathe Martin? As Dave says, it could be a while before any appear second-hand – although it is worth checking if Warco have any ex-demo at their open days (there is one in November), my son's mini lathe came that way with enough of a saving to pay for its tooling.
Apart from the brushless motor, the rest of the improvements can be easily retro-fitted to a second-hand lathe if you find you actually need them. (I fitted a speed readout like this **LINK** for less than a tenner including a case).
One problem with the old model's 80mm chuck is that it has a smaller bore than the headstock, so an 80mm or 100mm 4-jaw with a larger bore is a useful addition – at least with the mini-lathe, accessories like chucks, steadies, quick-change toolposts and milling slides are readily available, as well as the full range of spares.
Brian