I've never tried it, but someone told me that's what they use eBay for - post it and see what you get. Don't know if that's an unforgivable breach of eBay etiquette if you're not genuinely intending to sell. Otherwise, go to an auction house, it will be worth it for the laugh alone. I took a painting to Christie's for valuing and Polly and Max were hilariously posh and looked at me with pity when it turned out to be worth only a few hundred pounds. 'Well the sky's quite painterly, but he's not well known'. I've been retelling the story for months.