The auction of Yuga Labs’ 101 Bored Ape Yacht Club (BAYC) collection has smashed through expectations with a winning bid of $24.39 million.

The auction closed on Friday and was hosted by the prestigious auction house Sotheby’s, which had estimated earlier that the collection would fetch between $12 million and $18 million.

The bundle of nonfungibles consists of 101 Bored Apes and three M1 and three M2 “mutant serum” NFTs. When a Bored Ape token is combined with an M1 or M2 serum, it enables the holder to mint a new Mutant Ape NFT that keeps the same traits of the original Bored Ape but is depicted in a mutant format.

Taking the serum NFTs out of the equation as they are usually airdropped to holders for free, each Bored Ape in the collection was valued at an average price of roughly $241,000 or 69.4 Ether (ETH) at the time of publication.

The figure tallies in well above the floor price for Bored Ape NFTs on the secondary market, with data from OpenSea showing a minimum price of 38.99 ETH, worth around $135,000.

Yuga Labs also auctioned off a 101 NFT collection of its side project Bored Ape Kennel Club that closed on the same day with a winning bid of $1.83 million, at a price of $18,150 per NFT. The figure fell within Sotheby’s estimate of $1.5 million to $2 million, and beat the floor price on OpenSea of 3.09 ETH or $10.700.

Delaware-based Yuga Labs launched the BAYC on April 30, and it has since become a highly popular and sought-after project. Figures such as NBA star Steph Curry aped in by paying 55 ETH ($191,000) for a Bored Ape NFT late last month. Metaverse gaming firm The Sandbox also snapped up a Bored Ape for a record price of 740 ETH ($2.57 million) on Sept. 6.

Sandbox’s NFT depicts a golden ape with laser eyes wearing a sea captain’s hat. In a blog post on Wednesday, the firm revealed plans to port BAYC NFTs into its metaverse as playable avatars.

“The Avatar collections find additional utility for their NFT holders within our gaming virtual world. Through the interoperability of NFTs, they will be able to turn 2D collectible image NFTs into 3D playable avatars that are animated, can run, jump, socialize, play games, and interact with their other peer Avatars in The Sandbox,” the blog post read.

Bored Ape NFT 3749 Avatar: Source: The Sandbox

Related: OpenSea bug appears to have destroyed nearly $100K in NFTs

According to data from OpenSea, NFT sales volume on the secondary market cooled down in September, with top projects such as CryptoPunks, Art Blocks and BAYC all seeing declines in their seven-day volume of 85%, 82% and 69%, respectively.

Only one NFT project out of the top 20 has seen an increase in seven-day volume, with Vine co-founder Dom Hofmann’s Loot (for Adventures) NFTs seeing an increase of 8.42%.

NFT sales volume: OpenSea

Data from Dune Analytics also shows that NFT floor prices are on a downward trend of late, dropping from 1.02 ETH on Aug. 30 to sit at around 0.40 ETH on Sept. 9. However, this doesn’t necessarily indicate a bearish trend for the NFT sector, as the price can be impacted by new projects emerging on the market that sell for lower prices.