I sold my 70's oak Mayline drafting table 2 years ago for $450 in OK condition. Bought it in 1977. I think they sell for more mainly because they can be used as a piece of 'furniture' by an artist or crafter. Mayline still sells the identical table for $3354
https://www.mayline.com/product-detail.php?id=P1170
They also still make one very similar to OP's for $5590.
https://www.mayline.com/product-detail.php?id=P1172