In the 80's and into the 90's I would regularly go to Reggae concerts on a Sunday, usually Brixton Academy, Astoria or Town & Country Club (later changed to The Forum) then see the same concert again on the Monday night down at The Top Rank Suite in Brighton or Leas Cliff Hall in Folkestone.
As you say, concerts seemed affordable then. Brilliant times!
Best of all with the Reggae concerts at The Top Rank Suite, support would be by King Tafari Love Muzic Sound System playing roots tunes all night.
I remember being grounded by my Dad. I was 17 , just passed my driving test and promised to be home by midnight as I was using his car. I saw Clint Eastwood and General Saint at the TRS which finished about 11pm but it took me about an hour to get out of the car park. Happy days.