Families and adults attending Saturday night's preliminary final between Sydney FC and Perth Glory at Allianz Stadium will have to pay more than twice the minimum cost of last year's NRL preliminary final, played at the same venue.

The cheapest family pass for two adults and two children for Saturday's game - expected to attract 20,000 spectators - costs $98, compared with $45 for a category C pass for the Sharks v Cowboys preliminary final, which attracted 37,000 fans through the gates. The lowest-priced adult tickets cost $49 for Saturday's game, compared with $20 offered throughout the NRL finals series last year.

It follows a trend of high pricing for the A-League finals series with tickets for last week's games in Brisbane and Melbourne significantly higher than equivalent NRL and Super Rugby finals - in some cases double.

Adult tickets were comparable to AFL ticket prices for the first two weeks of their finals in 2016 while some A-League family tickets were more expensive. Last year's AFL preliminary finals tickets were considerably more expensive than that of A-League preliminary finals.

The prices coincide with disappointing crowd figures for the finals as the A-League is yet to attract a bumper attendance during this finals series. Brisbane Roar's match against Western Sydney Wanderers on Friday attracted 17,500 while fewer than 10,000 attended Melbourne City's home loss to Perth Glory.

The latter was a significant concern given Melbourne City boast marquee Tim Cahill among their ranks, have more than 13,000 members and finished with an average attendance of approximately 10,300 during the regular season.

Football Federation Australia controls the ticket pricing for the A-League finals series and receives the gate revenue.

"Ticketing structures for semi-finals matches are designed to strike a balance between the affordability for families and the premium nature of finals matches," head of the A-League, Greg O'Rourke said. "Ticket prices for the 2016-17 finals series were structured with families in mind with all family tickets lower or the same as last year when coincidently the two matches in week one of the finals were played in the same stadiums on the same night."

The ticket pricing for this finals series have been poorly received by some supporters. Brisbane Roar fans had to pay between $45 and $65 for adult tickets to last week's game against the Wanderers at Suncorp Stadium while Sydney FC supporters voiced their frustration at prices doubling regular season seats.

"There's a significant jump in prices from regular season games and the re-designation of seats. In some cases having people pay more than double than a regular season ticket because their bays have now been designated as platinum," Sydney FC supporter group spokesman, Grant Muir, said.

Prices aren't much cheaper in Melbourne for Victory's home preliminary final against Brisbane Roar at AAMI Park on Sunday. Adult tickets range between $45 and $69 while families passes cost between $90 and $138. The highest-priced seat at AAMI Park for Melbourne City's game against Perth cost $110, more than the most expensive adult ticket at the MCG for the first two weeks of AFL finals.