If 4,000 Rangers fans were to turn up twice a season, Kilmarnock would need to charge them £112.50 each.
If tickets are actually £40 then Rangers would need to take 11,250 fans to Kilmarnock twice.
If Tickets are actually £25 then Rangers would need to take 18,000 fans to Kilmarnock twice.
In addition, 20% of the ticket price to any football match is VAT, so for Kilmarnock to lose £900,000 they would actually need to sell £1,125,000 worth of tickets, making all the above examples even more extreme. I do not know how much Kilmarnock charge at the gate for an Old Firm game. Over to you guys?