I'm just stating my opinion...
What you think of my opinion, well...
I mention the difficulty in (TIG) welding cast aluminum, because...
I guess you can liken it to welding cast iron, but most weldors will not usually bother TIGing steel / iron - most would either blast it with a MIG or just stick it.
Due to the porous nature of the cast aluminum, TIGing this kinda material is not for the faint hearted or novice.
Blowing holes through cast aluminum, especially of this thickness (thinness? Is that a word?) is very easy, unless you really know what you are doing - you make it sound like any Joe Schmoe off the street can do it?
NO used shit - most expert weldors will agree that used welding equipment is a gamble.
This does not get you a tank - more money to buy or rent one...
Filling the tank with gas - more money...
Cart - well, I guess you can lug the entire welder around if you got the muscles for it...
http://www.millerwelds.com/products/tig/diversion_165/
The website lists it at a little over $1,600.
Looks like Miller dropped the power on their entry-level TIG.
Lincoln used to offer a TIG 175, but they don't list it on their website.
Miller used to have a 180 TIG?
http://news.thomasnet.com/fullstory/15631
But it looks like it got replaced by that 165.
20% rated duty cycle?
Geez...