Live in an afternoon
Fy writes the page and puts it online at your own address.
Side projects
Put a test page live on Saturday, send it to the people who'd buy, and see who signs up or leaves a refundable deposit. By Monday you'll know more than a month of planning would tell you.
Example data
Fy writes the page and puts it online at your own address.
Visits and sign-ups by day, and deposits through your own Stripe.
Decide go, pivot or stop. Stopping early is a good result too.