3.5 lb = 56 oz, $800/56 = $14.29/oz. for Zandor

$19/2oz = $9.50/oz. for BigBlock



Of course, the capital expenditures will favor Zandor over time, but I'll bet he vegged just a little bit longer. Probably has a better light, too.
But the main dif is between a personal sized grow and a commercial sized grow.

There's no need for a personal hydro grower to spend 800 bucks on setup. Sterilite, air pumps, stones, and tubing are all pretty cheap. PH and TDS meters can be found for as cheap as $20(TDS)-$35(PH). Then you can splurge on some good $10-$15/qt organic nutes.

DWC Bubble "Buckets" can be self-contained and non-recirculating, so no need of water pumps, outside res., etc.