On slabs...I am an ABO Knapper but beleive slab work is a good way to conserve material and if you are using it you likely are using other modern materials that will help in producing beautiful flake patterns which I really like to look at. To me slabs help bring about amazing patterns that can showcase the materials, form and style! This technique is one of many that modern knappers employ to explore pattern, color and form and become elements of importants beyond just function.
On pricing the amount of work and it's importance matters.
1. Production of larger orders has an economy of scale.
2. Market will play a factor-will you sell to hunters, yard sales, craft fairs, art exhibitions, museum gift shops, museum collections, friends.
3. Recognized and valued by others in our community. This can effect price when work is sold at themed events.
4. Technique can change the value it depends on what the buyer wants. Maybe they have a collect of only slab knifes or a museum only wants ABO work.
5 skill plays a factor also, buyers valuation through an appreciation of your skill...works with step vs no steps, how you employ pattern to the form, how you use choose to place a pattern of color as you build a point.