Kenneth,

1st, as others have said here about their teenagers having no interest in cycling... and my own distraction from cycling from age 16 to 18 and 20 to 22 for cars and motorcycles... i think your desire to cycle is really cool - especially since i know personally how it is perceived as so much cooler to drive during this age. actually this image doesn't end it just becomes less important and as you get older you're usually more secure to say who cares? so congrats on bucking the peer pressure image as driving as the only cool thing...

although i hope i don't sound too much like your parents::
1) be careful about getting in the habit of borrowing money. i made the mistake once and learned the hard way (mine took 2 years to pay off and i've been debt free since). SO many young people these days have debt and it just a bad idea. on the other hand, IF it's really that important and it's only 1 time, then think about it
2) although it's always nice to have good equipment, don't get caught up in the hyper-consumperism of the world today -- you don't always need the latest and greatest bike or gadget. as i alluded to in an earlier post, a good rider on a crappy bike is about 95% of the time better than a weak rider on an expensive bike. if you want to ride and be good, spend LESS on the bike so you have to work less to pay for it so you have more time to ride. Most of the guys who pay $3000+ for bikes don't have the time to ride them (note: pros don't usually pay for their bikes)

if i were you i would take the $500 you got saved up now and see if you can come up with maybe $100 to $400 or so from friends or whatever and i'm sure you can find a quite decent bike that will make you happy for quite a while. if all else fails, buy a total junker k-mart special. i disagree about the above comment about 2 months being nothing (i'm 31 and i've learned if you wait you miss out and life is plain too short). Yes, patience is a virtue, and you should not want it all NOW, but you only live once, and you should do the things you want to do ---> having ANY bike is what you need in order to meet your real goal to ride for the summer (patience is to wait for the expensive bike you really want)

but you'd be really surprised what you can find for a decent price of $100-$600 ---- as with most products, you have to pay a basic amount to get something reasonably good (say $400 for a bike) and after that you have diminishing returns: i.e. a $1000 is not usually twice as good as a $500 bike, nor a $3000 twice as good as a $1500... buy in the middle and you save AND buy used and you save... thus, i bet you could even find an almost ideal bike that's a few years old but great for like $500... maybe even someone one the bike forum in Toronto has an old but faithful they could sell you...