The all portrait priceas follow:
one people 12x16"--$68, 16x20"--$88, 20x24"--$108, 24x36"--$198
two people 12x16"--$108.8, 16x20"--$140.8, 20x24"--$172.8, 24x36"--$316.8
three people 12x16"--$149.6, 16x20"--$193.6, 20x24"--$237.6, 24x36"--$435.6
The calculational methods is: another 60% for add one people, so two people are 160%,three people are 220% four people are 280% etc...base on the single.
Combine photos - make people look thinner of fatter, or make a painting from different photos,and especially complicated background dress and personal adornment etc... will be add another 10%.