There's a modded Canon on the trader in your budget.
http://www.iceinspace.com.au/forum/s...d.php?t=125247
(No affiliation with seller)
I'd recommend a Canon - there's not much AP software available for Nikon. I'm a Nikon user, so I speak from experience on this!
Modded cameras will give you more Red colours in your AP images, at the expense of limiting it's use as a daytime camera without filtration.
Cheers
Andy