Maybe consider a refractor. Skywatcher has some 4", 5" & 6 " short tube refractors suitable for a simple alt/az mount, and within your budget. Though not the best for real high power stuff, they are still very capable instruments, allow plenty of light collection, and as an added bonus, can be easily made into terrestrial viewing scopes, something that a newtonian can't. This type of scope might be better suited if you are to set-up on a balcony regularly.
Have a look at the skywatcher section in the Andrews Communications website. These refractors are located about half way down the Skywatcher page:
http://andrewscom.com.au/site-section-10.htm