Would anyone know the price on a stoneware sitting ballerina by Loet Vanderveen purchased at Gumps in San Francisco?

Hi - I am actually on-line looking for informatin about Vanderveen on a "sitting ceramic piece" that my mother purchased, while I was with her, back in 1971 at Gumps in San Francisco. I wouldn't even have known it was by 'Loet Vanderveen' except that I found the receipt to it while I was going through the trillion boxes of stuff of my moms (she lives with me now, she'll be 89 this summer!) It was purchased 6-22-71 and was shipped back to our home in Greenwich, Connecticut. The piece is a little old lady seated, with flowers, in her hand and with a big 'peace sign' hanging around her neck! She has a light, greenish-gray glaze. When she arrived to our home mother promptly placed her on the mantle of our fire place! The cost on the receipt says $100, plus $3.43 tax. That was the cost at the time... but who knows her value today. She is in mint condition - not a chip. I found one piece advertized on-line that showed how hard it is to find Mr. Vanderveen's signature - if you didn't know it was there somewhere you'd never know what to look for. If I hadn't found that receipt... I'd have had to take it to a professional to have found out the artist! Cindy, West Palm Beach, Florida