At the first question, Theodoric glances over his shoulder to the brothers, but doesn't bother to ask. At the rest, he nods in affable agreement - until the final price, when he puts on a bit of a scowl of concern.
"Fifteen pence... that's, hmmm... five apiece... a bit steep for a half-day's boat ride, and us along only half the way at that... ten would be more affordable - our purse has to take us far, and back again... and you can fish on the way back, or as you please..."
He pulls a soft goatskin purse out; he has a couple, and the brothers more, but he pulls out the one with the closest to fifteen pence in it. He slowly shakes out ten into the palm of his other hand, a few at a time and counting out loud as they come, frowning as he hefts the remainder which is clearly around half, and then holding out the ten shiny silver pennies to the man in his open hand, and making sure the woman can see them as well.
He waits to see if the other is tempted by the sight of the hard coin, or at least offers to come down, expecting that a small reduction might be forthcoming. Whether a lower offer or no comes back, he'll accept that without further haggling, just so he can tell the magi he tried...
"... I suppose since you have to come back, not completely unfair... done," and steps forward to shake hands. A few pence is not worth any ill will of the other, and it's not his money. Having given it a try, his conscience and pride are clear.
He gestures to the others to get their gear in the boat, and waits until the local seems satisfied, then he clarifies the earlier small point of confusion...
"But no, no sailing experience - I meant we're willing to help, that our feet are not afraid of water nor our hands of hard work. Tell us what to do, and we'll help as we can. These winter days have grown short, so the sooner we arrive, the more daylight we'll have before dark."