I did black Friday once, in 2016 I think, anyway it was the year when suddenly all the big UK retailers decided to do it and there were scenes of people fighting over TVs. I reduced everything in the store by 25% mainly because there were things I was desperate to sell and also I was desperate to get cash in.
I did turn over £9000 that weekend, but at such a low profit margin that it did me no good. I am sure most of the items sold would have sold anyway (they were nearly all Gligas). On one I actually made a loss because the exchange rate moved in the wrong direction before Gliga sent the specially ordered violin. Even at 25% off there was no interest in anything other than Gligas (why is a very good question - these are popular items I am talking about, just not popular here for some reason)
Well now the delay in getting Gligas is nearer two months than one month. When demand outstrips supply to that extent you don't need to reduce prices. Most things in my shop are at or near the lowest prices in the UK already and I do need to pay the bills.
So sorry, but there will not be any Black Friday reductions from this shop. And I very much doubt if any shop is going to reduce Gliga prices when none of us can get them in the quantities we need anyway!