In the Sunday market where we get fresh seafoods, my wife always buy the small crabs because it is far cheaper in price by around 20% against the big crabs. But evaluating the big crabs versus the small crabs, it is better to buy the big craps no matter the price because it has more flesh and easier to eat than the small crabs that may be testing your patience. So when I buy crabs, it is always the big ones. That also applies with prawns and lobsters. The convenience of eating is my priority.
Females have to deal with family's financial budget. So, I think not only your wife but the whole female clan will go for the cheaper options. As far as taste is concerned your opinion is correct. Bigger version of crabs, lobsters, prawns are indeed tastier than their smaller counterparts. However, I do not have an idea how much the better variety of sea foods cost in your country, but they're pretty expensive here. Given that, your wife's point of view is quite reasonable.
