Well, this was a couple of days ago, and was $29.99, and not at the cheapest of pet stores either.Yeah this would be a 12" cube.. I'd love one of those deep blue ones but I've only seen them around $50
It might make it worthwhile calling a favorite LFS to see if they could special order for you. I'm not sure what benefit there would be to me listing retail stores in Northeast PA or Northern Jersey. But you could always drop them a line - info@deepblueprofessional.com and ask where any local retailers may be. It can't hurt, and in the name of DIY you'll still want lighting and filtration of some sort.
As for heaters, I've been tempted by the Cobalt neo-therm heaters - http://www.cobaltaquatics.com/index.php?main_page=product_info&products_id=33 they seem pretty well made, reliable and small enough to tuck out of the way.