I've never purchased something that I couldn't pay for immediately. I do use credit cards, but the balance is paid in full each month, when I receive my statement.
As for the trains themselves, most of my trains came from local trains wanted ads, flea markets, garage/estate sales, and local train shows (where most of the table holders were fellow enthusiasts, not dealers).
There was a period when I would pick out a few things from the Lionel catalog, and preorder them. But the items were always on the lower end of the Lionel price sale.
