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I think your idea of listing items at a slightly-higher price has merit, to achieve the "fuller" look you want. And there are a lot of regions in the world who shop based on availability, not price.
You want to find a niche market. I'd suggest you focus on export markets, where you might see little-to-no competition.
If you are based in USA, focus on Australia and Great Britain. They are English-speaking countries with generally-loose import laws. They are hungry for your products, and they are looking for stores like yours who ship internationally with low friction.
Become an expert with First-Class International shipping, and Customs Form 2976. Lots of stores don't want to bother with the hassle, so there's your opening. Cater to them, and your higher price won't as much of an issue.
You can also cater to domestic shoppers, even with a higher price, if you offer benefits that your competitors don't. Offer a 365-day return policy, or a price-protection policy (customers seldom bother using them). If your widgets are light, offer free shipping via first-class parcel. Or try free return-shipping.
There are lots of opportunities to succeed, even if your competitors have lower prices for the same items. Think globally, and test various promotions/policies to find out what works for you.
Does anyone know if the manufacturer can legally stop me from selling their product that I bought at retail? Could I be sued for this?
No and no. However, you should think about how you honor a warranty. Customers want stores who stand behind a product, not simply boot them to the manufacturer for resolution. Are you prepared to take returns on damaged/defective/unwanted products?