Any vintage lunchbox is a good seller, and Snoopy is no exception. Look for the metal lunchboxes. If a thermos is included, even better. Here is one that recently sold for $150.
Another item to look for is Snoopy coin banks. The true vintage coin banks are made out of ceramic and have a removable plug in the bottom. Here is one that recently sold for $167.50.
There are specific Snoopy Fire King mugs that are collector's items and have historically sold for over $250 each on eBay. This information is probably old news for most eBayers. The most popular one is the Snoopy Red Baron coffee mug made by Fire King. The latest one sold here for $95.
Vintage music boxes are another no-brainer, so keep Snoopy and friends in mind. You will get more if the music box actually works, but some sell in non-working condition. Don’t pass one up if you can get it cheaply. Here is one that recently sold for $120.
Character bedding and sheet sets also do well. What is interesting here is that crafters and collectors make other items out of the sheets, using the sheets as fabric or material. If the sheets have holes or are not perfect, that is ok. Be sure to put the words fabric and material in your title. Here is a listing for a set of twin sheets that sold for $113.
Not sure what your vintage items are worth? Use Terapeak to find out. You will be pleasantly surprised to learn what items in your home have value to collectors!