Random questions in the form

[yanokwa]

Yes. See below.

Display a randomized group of questions and display in a question randomized percentages (33%, 66% or 100%) of a price previously saved in an XLSform

The simplest way to do this is to put every variation in the form and randomly show one. See How can I randomly choose which of two questions to display for an example on how to do this with questions. The same technique applies for variables and groups.