I though - I must have seen Sabbath. In the early 70's we as a bunch of lads used to see bands at Newcastle (UK) City Hall - just a regular size city hall.
Anyway you can easily find gig listings for that City Hall from that period.
How about Elton John, Pink Floyd, Sabbath, Zep, ELP and many others. Ticket price? Well Elton John was quite expensive - 90p (so less that £1!) Most others were typically 60-70p.
This was in the very early days of outdoor festivals. The first Woodstock was in 1969, and the first Isle of Wight festival was 1970 (and still has the record attendance of 750,000). So landmark bands played small venues and Universities. I saw AC/DC in the University dining room at Southampton!
A golden age to see these bands close up. Ear bleedingly loud. Even at head banging 16 with my long centre parted hair and denims I used to shove cotton wool in my ears. Very weird back in the day, but at least my hearing is roughly intact.