How much did wealthy dresses cost in the 1800s in America?

The answer to this question is not simple. In the 1800's colonial America had several overlapping currencies all linked to the English pound. They counted with pounds, shillings, and pence. ( 12 pence per shilling, 20 shillings per pound). The prices are in this format. In 1800 a length of silk ( 5 3/4 yards) was 26 shillings. A pair of silk stockings was 2 shillings while a simple white dress was 5 shillings. Shoes ran 6-11 shillings for something simple. One of the things that must be kept in mind is that items like dresses and shoes were made to order. The people of 1800 didn't have the means to mass produce these items like we do today. They bought the cloth and paid a seamstress or dressmaker to make the dress. A cobbler would make the shoes and those would take several weeks to months before they were finally delivered to the lady who ordered them. It is the same with a dress. It took planning to get something in 1800.