I think it depends a lot on what you can afford and are willing to pay and also on whether or not you have a vehicle.
I think willing to pay is the only thing that comes in to play. If you can't afford it then you not in a position to be willing to pay.
For me personally, as I live in Plymouth and am travelling on foot this year, it makes sense to go from Plymouth rather than Portsmouth. The fare for a foot passenger is probably less than the train far to Portsmouth and back plus a ferry ticket.
Yes it does make sense for you to do that. It looks like it's about a £80 for you to go as foot passenger.
There's also the advantage that, on the return trip, I'll be hot, tired, sweaty and aching and I'll still be able to step off the ferry and be home in ten minutes by cab, rather than facing a long train journey with all my kit to carry.
Now this is the
real question. What value do you put on being able to take the 10 minute Cab ride. Previously I've always paid the extra to aviod the driving involved in the Dover Calias crossing. However, this year they have over stepped the mark. £350 + a night in a Hotel say €85 is more than I'm willing to pay. Going via the tunnel cost me £250 less in Channel crossing costs but £60 more in Petrol and 6 hours extra driving.
If your crossing was £150 more than the cost of using say Eurostar would you pay it?
t.