Newcairo,
It serves little purpose to come here, ask a question and then argue why the answers are wrong.
I went to
ebay.uk, searched for Bermuda SG92 and clicked on the 'sold listings' box.
There were 13 completed sales of which 3 were fiscally cancelled. The sale price of these ranged from £4.50 to a discount off £15.
That is the real world value of an individual stamp. Your strip of four may be worth a little more than 4x the value of a single. I think this places the real world value of your strip between £16 and £50.
It is a nice item but stamp collectors look for stamps that have completed a postal function, not just any function.