Denture Yes, you read that right. At a yard sale in 2019, my brother bought a set of used false teeth for $1. He promptly flipped them on eBay for $75.

Vintage road map Road maps are popular with crafters and collectors of oil and gas memorabilia.

Ugly Christmas sweater Mark your calendars: Each year in November, online sales of ugly Christmas sweaters start to spike.

Sea gla Red, orange and amber sea glass are particularly prized. I’ve seen 11 pieces of red and orange sea glass sell for $170 on eBay.

License plate That stack of old metal license plates in your garage is worth money. In a cleaning frenzy one summer, I liquidated 25 plates for $30 on Craigslist

Antique eyeglasse Your great-grandmother’s pair of wire-framed eyeglasses are likely gold-filled, which makes them worth $20 to $40.

Vintage hotel keychain Readers of a certain age will remember the plastic diamond-shaped hotel keychains (also called key tags or fobs) from the 1960s and ’70s

Driftwood Large pieces of driftwood are used in landscaping, furniture construction, terrarium design and taxidermy projects. Simple forms fetch $10 to $15, while bigger, more-interesting shapes can bring $30 and up.

Antique key Last summer, I sold several antique keys at a yard sale for $3 apiece. Online, buyers will pay $10 to $15 for a single, unique key.

Old coffee cup . A single jadeite mug can sell for $35 to $40.

Rotary phone Collectors pay a premium for working phones in bold colors like orange, pink, mint green and blue. I once saw a dark blue rotary desk phone sell for $180 on eBay.