Test ride, test ride, test ride! This means checking out all the dealers in your area, as well as finding local riders who will let you test theirs out. This isn't a quick process, because to do it right you should make a list & write notes for each test ride, then when you've exhausted all the test rides, go back for a second round with the same bikes. Test rides are a learning experience and the experiences of the second try are often 'way different. You can make up your own mind about prices after all the test rides, but the better ones will probably range from $1500-5000US. Look for relatively light stiff frames, comfortable seating, and efficient, well-thought-out drivetrains.

The transition from upright to bent IS major. Acclimation can take months, so renting tends to be impractictal. Beyond that I can't offer advice, other than to suggest buying used so that you don't get hit by depreciation so badly if you decide to resell.