Logistics of pre-sales for a product that hasn't been manufactured yet

I've been talking with a manufacturer in Mexico to get a quote for a product I've developed. They gave me the quote today and the prices seem good to me.

I put up a Shopify site and was thinking of running some ads to the site to presell the product and then ship it once it arrives.

This will help me to cover the cost of my first order.

But I haven't even seen a sample yet. (I've seen a photo of my sample, but not the actual thing.)

So the risk I'm running is this.

If I get a bunch...

Logistics of pre-sales for a product that hasn't been manufactured yet

from Logistics of pre-sales for a product that hasn't been manufactured yet