The value of Depression glass is not set in stone. There are so many variables! Value reflects supply and demand. Today, the supply exceeds demand. While baby boomers went wild over Depression glass in the late 20th century, many are now downsizing and want to get rid of their collections.
The value of a set vs an individual piece depends on who is looking for what when you attempt to sell. Depression glass appears all the time in online auction and sales sites so the availability is vast and changes rapidly. I suggest that you keep searching the sites to see what people are buying.
Frequently, collectors look for individual pieces or groups of pieces they want to complete a set. Some collectors enjoy buying a variety of pattern and colors. Some look for one color in a variety of patterns - say a person likes green glass so they search for all types of green Depression glass. So the value depends on who is looking for what on any particular day.
Don't count on earning the value suggested by sites like Replacements. While that is a great site, the value reflects retail pricing and that, too, is variable.
You can shop your set to a dealer, try several dealers to see what they will offer you for the set. If you wish to sell privately you can only ask a price and hope for the best.
I have visited sites that suggest having Depression Glass appraised by a professional appraiser. You might think twice about going that route as the service is quite expensive and usually reserved for higher end products. You may wind up paying more for the appraisal than the glass is worth.