The seller is constantly trying to put a price on himself, it's hard to find a common language and constantly shifting responsibility for his mistakes and poorly done work, trying to make fools of you.
Product prices are the same as everywhere else. There is absolutely no desire to have anything else to do with this store.
And before you don't speak well of your competitors, you should have sorted out your store. We dealt with your not-so-favorite competitors twice and everything was fine, on time and without incident. And most importantly, these people are able to communicate culturally and politely.