Вы должны использовать тот же метод, который вы использовали бы для sort
ing :
>>> my_list = [{88: 3, 68: 0, 6: 0}, {88: 2, 68: 1, 6: 0}, {88: 3, 68: 0, 6: 1},
{88: 2, 68: 1, 6: 1}, {88: 3, 68: 0, 6: 2}, {88: 2, 68: 1, 6: 2},
{88: 2, 68: 0, 6: 3}, {88: 2, 68: 1, 6: 0}, {88: 1, 68: 2, 6: 0},
{88: 2, 68: 1, 6: 1}]
>>> sorted(my_list, key=lambda d: (sum(k * v for k, v in d.items()), sum(d.values())))
[{88: 2, 68: 0, 6: 3}, {88: 1, 68: 2, 6: 0}, {88: 2, 68: 1, 6: 0}, {88: 2, 68: 1, 6: 0},
{88: 2, 68: 1, 6: 1}, {88: 2, 68: 1, 6: 1}, {88: 2, 68: 1, 6: 2}, {88: 3, 68: 0, 6: 0},
{88: 3, 68: 0, 6: 1}, {88: 3, 68: 0, 6: 2}]
>>> min(my_list, key=lambda d: (sum(k * v for k, v in d.items()), sum(d.values())))
{88: 2, 68: 0, 6: 3}
>>> max(my_list, key=lambda d: (sum(k * v for k, v in d.items()), sum(d.values())))
{88: 3, 68: 0, 6: 2}