I agree with baichai, don't skimp on the monitors, you'll just piss yourself off. On the low end there are the Samson Resolve 50a's:
http://www.americanmusical.com/st/aspx/i-SAM+RES50A/en/item.htm
M-audio BX5's:
http://www.americanmusical.com/st/aspx/i-MII+BX5/en/item.htm
Behringer B2031's:
http://www.americanmusical.com/st/aspx/i-BEH+B2031/en/item.htm
Event TR5's:
http://www.americanmusical.com/st/aspx/i-EVE+TR5/en/item.htm
I've only heard the Samson's, Event's and M-Audio's. I remember thinking the Samson's were a good deal for 219.00, I was impressed by the bass response on the M-Audio's, not bad for a 5" monitor, I liked the Events the best but I think I'm just more used to their sound cuz I own the PS8's and TR8's. I would suggest you take a CD you're familiar with down to your local music store and listen for yourself and see what you like the best.
Also, if you're interested in the Fantom-s check out
http://www.riksmusic.com, they had it for 1299.00 a couple of months ago.