Sorry for the inconvenience, but where did you get the Telegram username from? As I can't find the dealer's telegram ID on the reference link you shared, if it was truly from the dealer, then he might have been busy or something else. As I can see from the screenshot you shared, the last time he read your message was immediately after he said, Wait, please.
Also on this forum, he has not been online for the past few days; maybe something might have happened—a faulty gadget or anything—that could disrupt his internet access. If you are in a hurry, I would advise you to wait a little longer. The person in question has completed a lot of deals here, at least from what I can see in his trust list.
The OP is acting smart.
His old thread has his ID of Telegram:
https://bitcointalk.org/index.php?topic=5154316.0At the end on the Thread it says : “ Contact me here on the forum or on telegram : @eldon1”
To your 2nd point where his device could be faulty: He just replied to a friend who messaged him on Telegram for sales enquiry. I am happy to share snapshot in private as my friend is not willing to share his identity.
Any support to bring such reputed seller being bad would be helpful.