The pallet is painted with latex.
Well since you used it, charge her $30-35. $20 is way too cheap esp since you hardly used it.
Hmm. I think it originally costs around $50, right? If she's your friend, you should sell it to her for about $20 or $25. That's around half, which should be appropriate if you already used it (plus you know her personally). Hope I helped you! :)
