The wording of the rules states that you must either peruse/buy the souvenirs or buy a legendary object, but what if you cannot afford the remaining legendary objects? To the letter of the rules, it would imply that you must only choose this option if you *can* buy a legendary object, so players should determine what's in the pile of unbought items (easily done) before making that an option. More hand-wavey, we could argue if someone mistakenly doesn't realize he can't afford any of the remaining items, then chooses to buy a legendary object and picks up the remaining cards, he simply is barred from buying anything or resorting to the souvenir option.

I tend to lean toward the more forgiving option which is if a player can't afford anything, he just goes to the souvenir shop especially since the list of cards is public info obtained simply by looking at the players' holdings which are exposed.