Outdoors-
You'll be surprised how quickly it will all come back to you. The thing you'll probably notice most is lack of conditioning on your part? I know I did! If you've been couch surfing this winter start with some cardio now so you can spend some time on the bike you do choose.
I don't know how big or how much you wiegh but if you are of average build 5-10 180# and riding in the woods I think you would be happier with the 200. If your 6' 225 riding in alot of open areas I think you'd be better suited with the 300. If you were sittting on a 125 I'm guessing your closer to the first. Rider ability goes along way,i.e. I have a buddy a B rider(closer to an A), 5-10 185#, and he races the 300 in tight woods HS and places.
I'm 6' 250# and HS race the 520.
So here goes, my 2 cents, I'd try to pick up a 99-00 200E/XC in excellent condition,look to spend about 3800-4200, & take your time getting reaquanted with riding. The 200 will be very user friendly at first, it will penalize you for your mistakes, just not like a 300 would!! After some saddle time, and as you twist it more, it will be there for you and you'll love it. If, at the end of the season you decide to go bigger, you will have a bike you can sell and won't loose your shirt at time of sale. Keep in mind were kind of bias in here so no matter what size bike you chose go orange, in the end you'll be glad you did!
[This message has been edited by ripin520 (edited 02-28-2001).]