I want to set something up where I can offer the customer 1 sample at a lower cost than buying 1 of my units. But I want them to be limited to ordering 1 of each product. I sell cabinet handles, so there is a very low likelihood they would be able to order 1 to do anything with it. I'm willing to eat the cost on a discount for 1 unit per customer so they can try the product at a discounted rate to buying 1 plus shipping (I offer free shipping over $50 but almost nothing is $50 per item). Any suggestions on how to code this? Or use the standard settings to make this happen?