Given that the cars are normally worth less than a couple of thousand
There's a caveat to that: The ones worth less than a couple of thousand are increasingly either sheds or dodgy modified stuff. I'd be surprised if each of the ones pictured didn't require some remedial work for rust, and invariably pretty much any car for a low-ish price will need something mechanical doing sooner rather than later.
I'd say about £3k is now starting price in the UK for an MX-5 that you could hop in, drive and largely forget about - though even at that money you'd probably be putting a few things on your shopping list. While some of the stuff I've done to mine was out of interest rather than necessity, I spent my first year with the car giving it a full fluids and belts service, new brakes, new clutch, new tyres, an alignment... were it not for some perks of my job (i.e. free stuff) I'd probably have spent the value of the car itself in maintenance since buying it in February 2015.
Of course, even £3k seems low for someone who might then consider having a car restored - but these cars are now of the age where people are treating them as they would any other classic car. People were restoring MGBs and Cortinas when they were worth sod-all a decade ago, too.
Probably also worth throwing in the factor that this is Japan where it's relatively difficult to run an old car in general thanks to the
shaken etc, so a) if you own an older car you're probably already spending a decent wedge of money on it and b) there's more incentive to make sure it's as perfect as possible.
Anyway... I think it's pretty cool Mazda's doing this. Mazda still seems hugely dedicated to the MX-5 as an entity - it's pretty much responsible for the entire company's image these days - and it'd be great to see some original Roadsters given the full resto treatment. Wonder if they'll commission a reproduction of the Pioneer MSSS stereo that my car originally came with...