Road Cycling - Prospective roadie here.

I was interested in picking up a road bike as the lcal trail isn't so local anymore due to my moving to a flatter part of the city. In fact nothing is really local anymore. So that leads me to want to pick up a road bike. Not just for getting from point a to point b, but also for the excercise. My P3 is just not that comfortable when it comes to distance riding. So I guess any hep with the following questions is appreciated.

What size frame would I ride. I currently would ride a 20" mtb frame with about 2" of clearance from crotch to top of tube. I am 6'2".
Any reccommendations for an inexpensive bike, I don't have a ton of cash to spend, probably in the region of 500-600 max. (USD)
Why are road bikes so much more expensive?
would a comfort/touring bike be more suited to my needs?I plan on putting lots of miles, as the roads around here are horribly flat.

you can pretty much ride any size as long as you have clearance, but a more important measure is your reach to the handle bars... and for that you have to checkout bikes at the store to determine what fits you...

Go to Velonews.com and click on the tech section. That will take you to Lennard Zinn's column. Get to his homepage and find his fitting routine. It is simple to use and will get you close. Zinn is very tall and specializes in making frames for taller riders. You will hear from others to go to your LBS and get fitted. You may wish to do so, but I don't like wasting their time unless I am seriously considering purchasing from them. If you do go to the LBS, try more than one to see if they come close to agreeing on your size.

Then go to eBay. For $500 you will get a great used road bike. My suggestion is to stick with steel and brand names. Steel is generally the most rugged/long lsting material as well as the most comfortable.

You will definitely want a road bike if you are going to "put on lots of miles" at anything faster than 14-15 mph. Occasionally someone will show up on our LBS rides with either an MTB or comfort bike. After one jaunt for 35 miles at 17+ mph they disappear (off the back after a great deal of labor). If they are serious, they show up the next time on a road bike. Comfort bikes are not designed for lots of miles at higher speeds. Have to push too much wind in the upright seating position, if for no other reason.

Fit is of utmost importance. As for your budget you'll be looking at Shimano Sora components unless you find something used that's 3 years old or so. If you buy new you might want to check out Fuji. I have a Fuji Finest steel frame, Sora components. I've put about 2300 miles on it over the past two years and am pleased with it's performance. Of course, that's coming from someone who was accustomed to riding a 15 year old 12 speed Motobecane.

Another thing you might try is show up at a local bike club ride on your current steed. You can ask people if they know anyone who is selling a bike. We have club members who sell bikes from time to time at below the market prices. Shoot I knew a lady who was financially strapped and Diane our local mechanical whiz managed to put together a decent ride for her for virtually nothing. Club members hereabouts often donate deceased bikes to Diane knowing that the parts will end up doing something useful. So give it a try, what do you have to lose?

jcivic, I've got a bike that might fit you. You have a PM.

AS for why roadie bikes don't have much of a low end on the price scale, it's business. The bike companies realized that mountain style bikes, with their perceived versatility over and above what a road bike possesses, are desired by the majority of entry level riders. It does make sense, to an extent, but makes it hard for folks like yourself that don't want to break the bank to get a good roadie bike.

Hi,
there were a lot of good bikes made in the 80's and the 90's.
You will need to learn how to buy a used bike, learn which brands and models are desirable; and then spend some time shopping around. I was looking for an old bike to put on a trainer, picked up a sweet 20 year old bike for $150; and I am thinking of using it for my commuting as well as trainer time.

eBay is a real good option (as suggested above). I got a '00 Trek 2000 for $300 in great shape. I've already slapped 600 miles on it no prob. You'll love road riding and wonder how you ever got by w/o it, but give it about 100-150 miles...