There is no shortage of pricey retirement communities across the United States. Yet believe it or not, it is still possible to get a decent place for $100,000 or less. You'll have to pay for shiny and new (although sometimes it's possible to sneak in under $100,000 with a smaller unit in a brand-new building or community). However, there are a number of oldies but goodies out there -- age-restricted, 55-plus developments built in the '60s, '70s, and '80s that are still going strong and offer a wider array of less expensive units. To put together this list, we spoke with brokers in Florida, Arizona, and Pennsylvania and scoured real estate listings and websites.