I would have to agree with Brian that you will probably not find anything under $700 with 2-3 bedrooms in these areas. You may find something in Southeast Aurora that might work.
I think the best site for rentals is http://www.Rentals.com. Since this site is a pay site, it seems to have much better information and not as many scams. Please be careful on craigslist as many of our clients have run into many different rental scams.
P.S. If it sounds too good to be true, it probably is!
If you are looking to purchase, please check out http://JulieReddingtonRealEstate.com. You will have to factor in HOA' s, insurance, taxes, but you have the tax rights off's also which make home ownership more appealing.
Call me if you want to talk more in details about what you are looking for
720 226 4168