When it comes to Vintage bikes theres different Genres of collectors,Which You choose to delve into and start collecting is up to you and your wallet. Some people choose to collect bikes one from every Country/Region, some from one specific manufacturer, and some from very obscure builders, etc.

My only suggestion when it comes to starting,is to choose a frame that does not need paint or rechromeing. Those 2 things are the Biggest expense and cause of headaches when it comes to Vintage bikes. Spend the extra money and buy a frame with a paint job and chrome that are ready to build up. Buy a $150 frame that needs paint and chrome and your looking at an additional $250 to $500 for a repaint and another $250 to $350 to reChrome the forks and frame. That inexpensive frame just became a money pit.

Read up on all that you can before you start investing heavily. Good Luck.