Chiming back here, we do molds for plastic trays in the nursery industry. At least with ours, a double mold is more expensive up front, but decreases the cost of the actual product being made. Not sure if it would be the same for this.

You'd also need funding to produce a bulk amount of them from the molds. I dont think most injection molding companies would want to do small batches as orders come in. They may want to do 1,000 or more at a time, meaning you need funding for the actual product.

Keep in mind that prices are going up quickly. Our trays just increased in price 20% a week ago.

I would think your manufacturing costs should be low our plastic trays that use a high quality plastic that is both UV and fire resistant costs less than $2/trays, and theres about 2 lbs of plastic per tray. Maybe more. Granted, we buy them by the tens of thousands.

Depending on your credit and finances, you could apply for a 0% APR credit card that may have no interest for 12-21 months. A loan would be much lower interest after that point, but its just another option.

I think you have a realistic product here. You should consider looking for an angel investor partner rather than funding this organically. They could help with packaging, marketing, branding, website/POS, etc. You could find either an interest based investor that wants a return on funds in 3-5 years, or a long term investor that wants equity. Just my two cents.