If I wanted to trade up, the OP could buy my elderly Vios for 80,0000 baht. It's got at least another 100,000 km to go.
Or he could buy the one in the photo from a Chiang Mai dealer who sells to expats, with a one year guarantee. 121,000 on the odometer, good for another 200,000 km.
Your infatuation with EV's misses the point every mechanic in Thailand knows how to work on a Toyota, and their reputation for reliability is well established. How many mechanics know how to work on a Neta? The OP would then be the captive of whatever Neta servicing is available in his area.
Then there is the battery. What warranty does NETA have on that, and does it apply to secondhand vehicles?
At 300,000 baht, IMO the car is cheap for a reason. And 300K may not be such a bargain if the battery goes kaput prematurely.
There's a case in Australia where a Nissan Leaf battery failed. New price of the car AUD 50K, replacement battery AUD 38K.