What I did when I was getting back into riding after a 30 year break was:
1. I bought a Honda Rebel 250. I bought mine new but from looking at Craigslist I know they can be had, in good shape, for anywhere from 1000-2500. That was in July. That little bike was small for me (I am 6'4 and weigh around 225) but it could handle the highway at 80mph.
2. I rode that for 2 or 3 months and then I went ahead and bought my Harley (Soft Tail Heritage Classic). That was in October.
3. I rode the Harley all winter and garaged the Honda.
4. In the spring I sold the Honda for about $500 less then I paid for it.
I also agree with everyone telling you to take a riding course. There is a good one near me that has 3 or 4 different flavors of bikes ranging from 250s to 550s or so that you can use while taking the course. Good way to get a handle on what size bike you really want and by taking the course you get a substantial discount on insurance.
just my
.