Regarding your quote,「ったく、銀貨５枚とどちらが割に合うんだかな」,";ったく" doesn't make sense in Japanese. Is it "全く"？Something is missing.

"どちらが割に合うんだかな" means "Which would it better worth?" or "Which is more advantageous (profittable)?"

More common way of saying this is "どちらが割に合うのかな" or "どちらが割に合うの（ん）だか." I think "な" at the tail is used for the pourpse of emphasis or self-afirmation. It's a coloquial turn of phrase, but very, very rare to hear such an expression - 割に合うんだかな.

Regarding your quote,「ったく、銀貨５枚とどちらが割に合うんだかな」, ";ったく" doesn't make sense in Japanese. Is it "全く"？ Something is missing.

"どちらが割に合うんだかな" means "Which would be worth more?" or "Which is more advantageous (profitable)?"

A more common way of saying this is "どちらが割に合うのかな" or "どちらが割に合うの（ん）だか." I think "な" at the tail is used for the purpose of emphasis or self-affirmation. It's a colloquial turn of phrase, but it's very, very rare to hear such an expression - 割に合うんだかな.