Helen & Black Walnut, Its all down to the quality of materials used.
If the harpmaker is using low quality materials, he/she is going to make just an average harp. On the other hand, if high quality materials are used, the end result will be stunning (depending on the skill of the harpmaker) This type of harp takes a lot more time to make, hence big price difference. Black Walnut's harp for ex', I would imagine would fall into this category.
As re' mailing list, website is being updated @ the moment, you can always PM me in the meantime.
John P, thank's for your intresting post, very informative, I looked at the harpsicals website (thanks Helen), great value-but like any musicle instrument you only get what you pay for. John P's comments, I thought where pretty spot on. More about the lap harp soon.