Yes, I know what I'm doing, but this OP wants to do things which have long long lists of possibilities.
Therefore, if he input each and every t-shirt, (hats, hoodies, jackets) the various sizes and colors, there's the first part of the equation.
Next, he needs to add in if a digitizing cost needs to be put in and about how long it will take in let's say 15 minute increments. Those prices could all be inserted in the program ahead of time and the button pusher can choose any of the variations.
Then, will it be screen printed or digitally printed. How many screens will be needed, how many cleanings needed and so on and so on. Each and every step could be put in as a separate item with an attached cost to it. Sure it's gonna be a lotta data input, but once it's in, unless the company he is buying from goes outta business, he'd just hafta do the same thing for a second, or third or however many manufacturers he wants to include.
By having all the subtitles, he could do virtually anything, just not have pictures in it. You can make subtitles after subtitle, til your hearts content, but hey, whadda I know ?? I'm just a dumb schmuck making signs. However, when were dong flatstock screen printing, we did the same thing there and many of the old set ups translated right over to flatbed screening. No one on the outside knew the difference.