How can you make any money at this? Printful is expensive and you offer free shipping on orders. Say one of your women's shirts runs 22.99. Printful charges 16 for the shirt and 5 for shipping, so you're only making 1.99 on that order. You're going to have to sell a whole lotta shirts! Are you planning on doing away with the free shipping at some point to increase your net or are you doing this for fun?
I only ask because I was considering using printful for our online shirt sales so that I wouldn't have to do much but they ate up all the profits. If you have the cash to pay upfront, screenprinting is the way to go.
I would remove the login requirements to generate a "budget" until you want to save that budget. You could also have additional features that are unlocked only after an account is created. Also, I would offer other currencies in addition to the £.
Just my 2 cents - before you ever release anything to HN, make sure that what you have works 100%. You can always add other functionality later. You would have been better off waiting to submit with the SSL cert working and limited functionality with a poorly designed website than submitting with a broken SSL cert and no domain name.
I worked for a company years ago that was in the same situation that you are in now. I was the first employee brought in to assist with the more day to day operations of the business. Things went well for a while. We added on more staff and I moved up and that's when I started to see the problems with the founder. His lack of management skills began to take its toll and the company was dead in the water six months later.
Dealing with tech is the easy part, it's the people that will get you.
I only ask because I was considering using printful for our online shirt sales so that I wouldn't have to do much but they ate up all the profits. If you have the cash to pay upfront, screenprinting is the way to go.