I'm following this thread too. My clients are not likely to pay online, they will pay via invoice. Because of this, the PRODUCTS functionality is not of any use for me. According to Squarespace the PRODUCTS feature assumes an online transaction will take place.
Squarespace please come up with a solution!
@MarieMF - How do you work around that? Are you doing it through email? I've been thinking about either finding another platform all together, or attaching a link that would take them to a functioning order option. I'm pretty disappointed in the product platform on Squarespace. I built all of my products and realized that it forced shipping and didn't allow me to change the category, so I had to rebuild everything as a service. The other frustration is SS requires a billing address, even though the only payment option I have is paypal. It's unnecessary. I also can't see the Venmo option anywhere. I'm getting close to quitting Squarespace.