melomania said:
3) what do you plan to ride- MX/SX tracks, woods, fields with friends or ?????
woods, fields, on road
The "on road" part would make me recommend a "dual sport" bike, which is going to force the equation to be limited to four stroke models.
The real question will get down to how much on road vs how much off road. The big difference is the tires. In order to be legal on the road you of course need the license plate, mirrors, turn signals, headlight and taillight. You also need DOT approved tires.
The mirrors are usually the first casualty of taking a dual sport bike off road. Just passing too close to a bush will snap the mirrors off. Laying the bike down is generally pretty hard on the turn signals. People who use their dual sport bikes on the road today, but off road tomorrow will often take the mirrors and turn signals off when they leave the road. Those who ride their bike from home to the off road location either ride very carefully when off road, replace mirrors a lot, or simply run without while on the road and risk getting stopped.
The tires are a bit more difficult to deal with as they are not something that you can just change when you reach the edge of the dirt. DOT approved tires generally suck off road. The big knobby tires for off road would be terrible at highway speeds plus the asphalt would tear them to pieces in very short order.
Many of the major manufacturers sell dual sport models, such as a Yamaha XT225 or several models from KTM. Depending on the state you live in some regular dirt bikes can be converted to dual purpose with aftermarket kits (to add the mirrors and lights).
Since your price range will require buying used your best bet is to buy one that is already street licensed. You will probably need something about 10 years old to get into your price range. In a four stroke I wouldn't recommend anything below 225cc. If you live in a major population center then I would recommend checking out Craigslist.
Rod