Brain-Teaser 466

From The Sunday Times, 3rd May 1970 [link]

The ferryman collected 5s. when he took six horses and two prams across the river, and 5s. 9d. when he brought six bicycles and three wheel-barrows back. He is at present collecting 4s. for two wheel-barrows, three prams and a horse.

His idiosyncratic tariff of charges is for vehicles and animals only, and not for people.

How much will he collect for his next cargo, which awaits him on the far bank and consists of one wheel-barrow, one horse, one bicycle and one pram?