A concept trailer for what? Because at least last I heard, concept trailers are ignored for 1) funding, 2) writing, 3) direction, 4) DPing and probably most of the other stuff too. If you want attention from the film world, you have to go the whole hog and make a fleshed out short, like the Portal and Mortal Kombat ones (Trachtenberg and Tancharoen respectively, I believe).
If you're just wanting to make "a cool piece", kinda like an old school RocketJump thing, then fair enough.
$1k buys you maybe two weeks of build time/materials. I don't think a suit like this could be put together in that short a period of time. I'm working on a screen-grade BR, if you're interested, but in terms of suits, your cheapest option is probably seriously flying someone out who'll act for free (assuming domestic return flights are still in the $300-450 region) and run'n'gunning it crazy fast while they're there.
