I want a bike to go on ridiculous cross-country trips on. I'm a skateboarder, so visiting several states and checking out new parks and traveling just seem like the greatest trip to take.
That said, I'm a college student, so price point is definitively a tough one for me. I'm looking at the ballpark of 4-5K. Or lower.
Feel free to correct my thinking at any point if you find fault:
I need a bike that'll get good gas mileage (fuel injected?), require relatively little maintenance (shaft drive?), take me far without complaining; that's to say, put up with empty gas tank run after empty gas tank run without rest (liquid cooled?) [horror story on this at the bottom of this post], and be able to easily ride two-up with a little baggage on a freeway at +80mph for hours at a time (+500ccs?)
Anyway, that's what I need, I'll likely keep my gz for commuting to school and any around-town riding..
I was really looking at some C50s: the fuel injected, shaft drive, liquid cooled, 800cc's sounds like it should do the job.. (right?)

I've seen some C50s and M50s in the 3-4K ballpark in my local craigslist.
Anyway, on to my horror story.... Maybe you can help me shed some light and tell me what lessons i should have learned from this experience:
I bought my gz250 from a dealer that, if it wasn't for a close friend saying an acquaintance had landed a good bike at a good price, seemed a little shadier than what I'm comfortable with. I bought the 250, ran it for a few hundred miles, changed the oil and went on a miami->gainesville trip (300-400 miles). the bike got up to gainesville fine, i checked the oil before heading back down and it was full, but halfway down - in the middle of nowhere - on a lonely stretch of road - around midnight - on a sunday - (try saying that one 3 times fast

Ended up paying around 6-700$ in repairs from a reputable dealer for a damaged piston and other engine damage.
I wish I could say that was it, but it's not:
I had to go back up to gainesville to start school, and i ended up forced to take my bike up since I couldn't find another way up. I rode it very gently (50-55mph ALWAYS), and stopped to let the bike cool for 20ish minutes every 45-50 minutes of riding ---- as the mechanic had advised me to----. He'd told me that the bike simply wasn't made to handle that kind of a trip, that 60-70mph was in the wide open throttle ballpark for that bike, and that the tiny oil capacity and air-cooled specs of the bike simply lent the bike to overheat and start using up oil if ran like that for such time.
Well, obviously being super careful wasn't enough, because i pulled over at some point after the bike felt funny, and I was leaking oil out of one of the head gaskets. Oil was maybe halfway to full. I topped it off and it sounded fine, no engine blown repeat or anything, but leaking nonetheless. And this is less than 1000 miles since i spent what accounts to several months worth of ramen noodles to get it fixed. Its still leaking, not too badly. A good friend of mine that knows his way around engines better than I do says that I blew a head gasket but probably didn't do any serious engine damage. He said I probably need to spend about $100 to get the two surfaces of the engine that meet at the gasket machined to be perfectly flat, a new gasket put in, and that should be the end of it.
I don't understand how the couple guys on this forum that have done long road trips with 250s have gotten away without any engine trouble. The kid with the rebel even said he ran it wide open throttle most of the time, and the only reason his engine got blown was because he forgot to close the oil drain or something along those lines.
Am I just unlucky? Should the bike be able to run wide open throttle for hours at a time? Its air cooled, but jeez I'm doing 60 or 70, shouldn't the air cool it down really well? I've heard all these crazy stories about people going across hundreds of miles on 150s... Do they just have to stop every 30 minutes or something? What's the deal? I felt like stopping was necessary only because your body couldn't handle going nonstop, not because the bike couldn't. I always thought once you got an engine to operating temperature and went highway speeds to keep it cool it shouldn't overheat.
Anyway, that's my rant. Let me know what you think, what lessons I should've learned, or any erroneous thought processes. Thanks! Hope to meet some of you guys someday.