As Yanoska said, it is extremely difficult unless you will go and get the efficiency. I had to turn down two clients with a budget of $700, I wasn't able to help them. Rentals are very expensive. If not the efficiency, try to get together with someone else and rent together. You will get much better deal, better and safer location etc.
$650.00 is a little tight...and having less than 3 months rent (first, last & security deposit) is not going to be a very easy task. You may have to consider finding an owner willing to accept those terms. Depending on the location, most 1/1 I have reviewed lately are $900.00 - $1,100.00 and they do want those 3 months.