Trying to keep this as brief as possible, I need a booking process that's multi-layered. I need to create it for a nail salon who will have packages in a tiered system as one layer, but after that the length of the nails they want is another variable, and it has to operate separately from the packages because it's a variable relevant to each one. After they select the package tier and their nail length I could honestly work with that but it would also be nice if I could offer add-ons as well that would automatically adjust the price. Based on what I'm describing would this be possible with TidyCal?