I'm not really into the status of your (seller) account, but that .dat file(s), there's no assurance that anyone can guess/brute force its passphrase, its a waste of money, time and resources imo.

I will be wary to buy such stuff, marami ng ganitong case na sangkot na scams, op has flagged and received negative feedback kaya take your own risk

This is a scam. Why would anyone sell wallet with that much balance?? and it's impossible to crack password so avoid this user at any cost.

What's the idea of selling 176 bitcoins for ~$300?

So, since when was Bitcoin Core have a watermark containing the letter X

I downloaded the video so deleting that video doesn't mean anything.

Note the watermark is present even after a new window has been opened which means that it is on the interface and has not been set up after finishing the video.
The image in the background is modified, so it does not guarantee that you are using the real program.

You have proven that you are a scammer, since when did Bitcoin core wallet contain the dlpcex logo?
This means that the version that you showed in the video is not the official application, but rather an attempt to scam.
The second point, owning the file does not mean anything if you cannot decrypt it, and you cannot decrypt it unless you know part of the password and it was possible to guess it.

Tagged.

No need to ask, you must provide proof at the first place. How can you attract buyers without any proof on what youre selling.
The question is, do you have proof or its only a lie.

Warning: a very popular scam method, avoid this user in any case.
You made some adjustments to the image to make it difficult to track using reverse image search.
you can find many of this screen shots using google and edit it to any amount example

Warning: a very popular scam method, avoid this user in any case.
You made some adjustments to the image to make it difficult to track using reverse image search.
you can find many of this screen shots using google and edit it to any amount example