Wakefield College do it for student cards. Might be worth contacting them

Not on entry but you have to put credit on it and then scan it on the printers when you want to print something out, so there is some intelligence in the cards.

For a relatively low cost approach, you could just have a card with a photo, name and barcode printed on it.
You'd need a barcode reader attached to a laptop on the ST turnstiles.
At the simplest level the operator could just match the name on the card to the name stored on the computer from the barcode.
People could make a card with a photo and barcode, but the barcode wouldn't match the name on the computer.
For further fraud protection, the database could spot double use to prevent cloning.
The information from the database could also be used to track each ST holders attendance, when they come and what time.

edit. Thinking about it, the database would have to be run from one computer so that the cards couldn't be passed to someone else outside the ground, and just use another turnstile. Although that would be a bit desperate.

Glastonbury tickets have names and photo's on their tickets, you take your own pic and send it online, if the picture is accepted, it's then posted on the ticket.

Or a biometric thumb print, commonplace in many uk schools these days, operating cashless systems, signing in, library, door entry etc etc.
The systems all feed into one or more central data bases also, something else that would benefit the club.
These systems are all leasable as well as buy able and the lease price isn't hugely different.

Swipe card with photo id would prob be the best system, with either full or half height external turnstiles. Systems vary but would be supplied with personalised software. For members/ season tickets holders how many turnstiles would be required and at what locations. A typical system would cost around £165 a week depending on the installation .
Maybe the club could come to an agreement with some advertising or a box .