i would imagine that they want something not only upscale but also unique, after all they are competing for the donation dollars with other charity organizations and the competition is getting tougher each year. I think you need to ask who will be receiving the thank you gift. Women, men, both? I think something very obviously handmade, very luxurious - think made from satin or velvet with embellishments. Perhaps a draw string gift bag of cream colored velvet with a satin and lace applique embellished with some pearls and filled with Lady Godiva Triffles. for the men maybe a silk bag in a plaid with a best seller novel inside. The applique could be as simple as a holiday appropriate symbol, the logo from the charity, or the words "Thank you." A simple hand written thank you card should be inside.