Just keep in mind that if you do post using letter rate, if you don't register the letter (around $3.00) you leave yourself wide open for buyers to open disputes for Item Not Received as there is no tracking, regardless of whether they received their item or not. Unfortunately these days eBay is full of dishonest people who will do or say anything to get a "freebie".  Not all buyers are like this, but there are plenty out there!