You may be right in saying other printers have larger build volumes, but the text also says “the largest print volume of any desktop 3D printer in its class”, whatever class means.
I do not want to sound like a Lulzbot cheerleader but
The Creatr as dasfiend said has a smaller build volume.
The RapidBot Mega has a build volume of 750 x 250 x 200mm, which is actually smaller in two axes than the TAZ.
The Glacier Steel from InDimension3 is $3,300. Much cheaper you say?
The Makers Tool Works’ MendelMax 2 build enveloppe is smaller and does not ship fully assembled.
How about getting your facts straight before throwing accusations…
Also, are all those open source? Are all those RepRaps? By definition a RepRap has printed parts, which drives the price up (3d printing is still a costly process). But to many this is an acceptable trade off for getting an open source design, and one which can be replicated.