I’m having a garage sale, I came across porcelain dolls I want to sell, how much should I charge?
They weren’t expensive dolls, but they are collectables and a couple have certificates with them. How much should I charge?
Answers below in Comments Section

Check on ebay and see if you can find similar dolls and see how much they are getting for them. Usually, garage sales are for more common, cheaper items. Collectibles are better sold on ebay or even craigslist to people who collect them, not little girls visiting garage sales with their Moms and want a $2.00 doll to take home.
sell them on ebay of kijiji