I don't think that's true. Here are two recent/upcoming Android 4 devices with 320x240:

Samsung Galaxy Chat B5330 http://www.gsmarena.com/samsung_galaxy_chat_b5330-4866.php

ZTE Style Q http://www.gsmarena.com/zte_style_q-4602.php

A couple of more devices which are reportedly coming soon: http://goo.gl/F411K

These are cheap phones, though I imagine you'd get a much better deal if you spent the same amount of money on a used Android phone.