Aberdeen
 

A walk-up single ticket from Aberdeen to Cork costs £48.50, less than a walk-up single from Heuston to Cork (€66). Routing is via Holyhead-Dublin Irish Ferries, and the journey can be completed same-day. Crazy, eh?

What is the cost of a walk up single to Aberdeen from Cork? Could this be used to get cheaper single fares?

I'll try asking in Kent station when I'm there next weekend. My prediction is "wha?"

Oh, and if you want cheaper single fares within Ireland, online booking is probably going to remain cheaper :)

To be honest, I've only ever bought a walk up single for a journey as long as Cork-Dublin once in my life. That was earlier this year when Cork Airport got closed by snow and I had to get up to Dublin for an alternate flight. Otherwise whenever I'd needed a single and been prepared, I used either an online ticket or a credit union ticket.

The trick is to go via Holyhead, via Stranraer is €70.

Cork to the Dublin ferryports should be a €20 add-on to a rail and sail price. So Aberdeen would be €20+€40 = €60. If you only went to Bangor (in Wales) it would be €20+€35 = €55.

It's the same here:

London - Holyhead - Dublin is £31.50 single, irrespective of time of travel.
London - Holyhead, on an anytime single is £127.00.

Travelling short is allowed in the UK, though.