probability is about .95 that the 95% confidence interval will include the true population parameter. On the other hand, 2.5% of the time the highest value in the confidence interval will be smaller than the true value, while 2.5% of the time the smallest value in the confidence interval will be greater than the true value.
Set prices with room to move. Most people expect prices at garage sales to be just the starting price and are about 25% to 50% above the seller's (ie your) bottom-line price to allow for negotiating. The amount depends on the condition of the item and how much you are prepared to haggle.
A garage sale (also known as a yard sale, tag sale, moving sale and by many other names) is an informal event for the sale of used goods by private individuals, in which sellers are not required to obtain business licenses or collect sales tax (though, in some jurisdictions, a permit may be required).