I have no doubt that your thinking is spot on.
I have no idea where to source outside of China, but I think it would be worth looking at ordering in an MOQ of units for some test marketing.
Visit some sites like alibaba, trade key, dh gate, global sources and so on. Talk to some manufacturers direct and see how small you can get that MOQ down to, and go to town on haggling about the price.
Don't just concentrate on Chinese suppliers, throw some Hong Kong and Indian suppliers into the mix as well.
Not sure about the US market, but on the Australian market if you could land, list and post them for around the $30-35 for 16gig, then I think you would have a very viable alternative.
I know you may be able to get a little more because yours are in stock, but only test marketing would tell you what you could get away with before customers went with the imported option.