Ya, I looked at the Dewalt welding horse as one of those things that could be useful in an emergency...and that'd be fine. It's better than nothing.
However for 95% of your on-site welding it'd be almost the same price to pick up a dedicated welding table and position it on a couple of saw horses.
The Dewalt costs $200 and is manufactured from 14 gauge steel, .078" thick. As an example a CertiFlat 2' x 3' table costs $250 and is .188" thick. It's less portable but a lot more robust.