Every now and then, people clean their houses to make them as presentable and livable as possible. During the cleaning process, they tend to sift through boxes to locate and discard objects that may be old, seemingly unusable, or invaluable. As it turns out, many objects people find lying around their houses can be worth a lot of money. Here’s a list of household things that may be surprisingly valuable for homeowners:

1. Gold coins
Rare coins and notes, such as the Australian 1930 penny or vintage dollar notes, are worth their weight in gold today. Coin collectors across the globe tend to buy old coins for huge amounts in auctions. Additionally, the value of gold keeps rising. This makes it a high-priced commodity at almost any point in time.

2. Sporting merchandise
Iconic sporting apparel and accessories have the rare benefit of becoming instantly timeless when the specific sporting event they are associated with ends. For example, if someone finds a branded jersey they wore to an NBA or NHL final a decade or two ago, the likelihood of fetching plenty of dollars by selling the jersey now is very high.

3. Vintage magazines
Old magazine copies tend to increase rapidly in value with time. So, if someone finds a copy of a fashion or sports magazine from the 1980s lying around their attic, they have a valuable collector’s item that will bring them a lot of money.

4. Christmas ornaments
A box of vintage Christmas ornaments can fetch hundreds of dollars today. The rarity of old German “kugeln,” or ancient hand-blown glass balls, coupled with today’s inflation rates, makes these ornaments surprisingly valuable.

5. Stamps
Collectors’ obsession with postage stamps is well known. Therefore, old envelopes and letters containing them must be preserved and sold.

6. Cassette tapes
Cassette tapes are a relic from an older, more romantic age. Their complete obsolescence makes cassette tapes extremely valuable today.

7. Watches
Vintage watches are a veritable treasure chest in today’s world. So, if one finds them lying around their house, they have found a valuable commodity worth thousands of dollars.

8. Vintage cookbooks
A running theme throughout this article is the increasing value of old books. Like old magazines and yearbooks, old cookbooks also gain value due to the seemingly diminishing presence of physical books in an increasingly digital age.

9. Old documents
Documents such as old contracts, bonds, and treaties are worth their weight in gold in today’s age.

10. Concert or movie posters
Iconic movie posters, concert tickets, and other memorabilia become collectors’ items quickly. This dramatically raises their monetary value.

Some of the other things that could be highly valuable are old VCRs, vintage microphones, glassware, and childhood toys.