Well, the Avengers budget was huge, and Ant-Man's will probably be pretty large also, but you need to realize this test footage was merely a way to see if and how well the shrinking/growing effects could be pulled off. If they couldn't, Ant-Man wouldn't have been green-lighted at all, let alone given a big budget. Each movie is it's own investment with it's own budget, so even though it's all done by the same studio, they're different projects. The budget of Avengers has no bearing on Ant-Man, though it's profits probably do in terms of motivating them to make Ant-Man at all (again, it's been on the back-burner for 8 years at this point). So my point is that they had a limited budget, if I had to guess somewhere in the $50,000 to $150,000 range, most of which was focused towards pulling off the shrinking/growing effects, less on hiring artists to design a version of the costume and then costume designers to create it. That process alone usually accounts for quite a bit when these super hero movies go into production. Screen testing costumes to make sure they look, feel, and move "right" is also a usually expensive and time-consuming process.
So yeah, I was merely saying not to make much of the costume in this, as the actual Ant-Man costume and look will have likely had considerable more time and money put into it.
Are you sure about that? I think if production had started it'd be all over news sites like what's been going on with Iron Man 3 and Thor 2 more recently. Also, Ant-Man still isn't scheduled to come out until late 2015, so I wouldn't expect actual production to start until late this year and into early 2014 at earliest. Granted, pre-production is going on now, and has been for years (the Ant-Man movie has been tossed around since 2005 or 2006, well before even Iron Man). Stuff like character and set designs, script being finalized, casting potential actors (another reason I know filming hasn't started--or significant production of any kind other than preliminary--is no actor has been cast as Ant-Man, that'll happen before actual production begins), etc.
Matter of fact, this article from mid Feb of this year (when you claim production started), says Edgar Wright (the writer/director) was still finalizing his work on The World's End, the movie he's doing before he starts on Ant-Man.
http://m.voices.yahoo.com/edgar-wright-discusses-ant-man-12006650.html
If I had to guess, work on that film will continue for at least a couple more months (editing, scoring, promoting) before it's release in October of this year. I'd expect Wright to finalize the Ant-Man script during the summer after he's wrapped work on The World's End, and start the casting process for Ant-Man (along with overseeing set production, special effects planning, etc) late this year and into early 2014, with filming starting in early 2014. This will allow a nice year and a half window to complete filming and finish the many special effects shots this film will likely utilize.
But yeah, there's no way actual production has started yet. Pre-production, absolutely, but this film is a perfect example of how drawn out the pre-production/script-writing phase can be.