I know for sure you have read a couple of threads about this topic, but this stands out. 
Here is everything to know about it...

The CryptoPunks & Bored Ape, to mention a few, are 2 of the most well-known NFT art collections. To newbies, these collections mean nothing more than a collection of monkeys in bright colors who look bored.
But, NFTs’ value comes with tons of exciting factors.

Metrics to consider when buying NFTs
NFTs are digital assets stored on the blockchain and they cannot be exchanged, replaced, or removed.
The 5 main metrics to look out for:
Rarity Rank
Estimated market cap
Team & Community
Provenance
Vision

Rarity Rank
Rarity is a vital metric to assess.
The rarity score, which Rarity created as a statistic to assess the potential value of the NFT collection, is a helpful metric.
NFTs with a higher rarity rank could have extra special NFT features plus an edge over others.
Estimated market cap
The estimated market cap is by calculating it through multiplying its 7-day average price by its total supply.
A High EMC means that there are more owners of the tokens & they may be willing to pay a higher price to obtain the NFT from one another.

Team & Community
The team's commitment and professionalism are a win for me
Any project that lacks a strong community is doomed, which is why it's difficult to know if a project will pop or fail before it mint.
"The tip of the spear is the community."

Provenance
“History of ownership behind the NFT”
Provenance helps you to utilize the blockchain to confirm ownership information changes, it is a crucial statistic for assessing NFTs.
Only one original can be linked back to the original creator, protecting your buy.

Vision
This is not a roadmap but a Vision, which is why you want to invest in the project.
what we are believing in—a vision. a plan outlining the goals, values, & financial approach.
Being sure that the team is committed to the vision & that it is for a long term.

Bonus
An additional metric is “The art” This is quite significant.
The artwork must be visually beautiful, intriguing, & attention-grabbing.
They must be varied. If they have the same appearance, the project as a whole may suffer.
Sometimes, the ugly artwork pops too

Final words
Market dynamics decide how valuable NFTs are, making it impossible to accurately forecast where the NFT space will be in the future.
However, by conducting thorough market research and utilizing the metrics I've provided, you can raise your chances of success.