Be patient. Black friday is coming in the states in about 5 weeks. Yesterday, abc warehouse had an acer system listed in slickdeals for $241 with amd tri core and 4 gigs of ram. A great deal that sold out fast. Keep looking daily. I also use fatwallet for deals.
Unfortunately I am attending school in Canada and Black Friday does not take place here as Canadians celebrate Thanksgiving in October. As well, I will need this computer as soon as possible, 5 weeks from now the project will already be over.
Basically, IMO you'll need a Quad-core CPU, around 4GB of RAM, and a moderate performing graphic card.
With budget in mind, I suggest an Athlon II X4 2.8-3.0GHz, any decent brand dual channel 4GB RAM, and an AMD Radeon HD5770.
As for the motherboard, I suggest to look for a micro ATX, since it's usually cheaper and only supports single GPU. Although upgradability will be an issue, but with your budget preference, this might be the better option. Since you won't crossfire, don't waste your money for features you don't need. Make sure it's compatible with the Athlon and DDR2/DDR3 RAM (whichever you prefer, although the DDR3 is faster, but not by much). The form factor also decreases the power consumption, although not by much. Probably by a few watts.
And don't forget the PSU, for the suggested setup, you'll need at least a 400-450W of good quality PSU with 80+ efficiency and active PFC if possible. Then again, a good quality PSU does include both features as proof of reliability. It also usually comes with a long warranty, around 3-5 years.
As for the case, any mid tower ATX case with side vents + fans, rear exhaust fans is enough for daily usage.
Other components, ODD and HDD. For the ODD, get a DVD-RW, just in case you need to make copies of your project. The HDD, get a decent capacity according to your preference, a 500GB capacity is usually enough for most people.
Monitor, keyboard+mouse, you should be able to choose according to your liking. I don't know how a monitor affects 3Ds Max performance, but it sure is crucial for gaming. With this in mind, any 5ms response time at, again, your preferred resolution should be enough.
Since I don't know the pricing and availability in Canada, I can only suggest the guideline for your purchase. Sorry...