It looks like it will be much easier to buy a kitplane that is already approved by die PFA. XAIR / RV9A, RV12 / JABIRU / Europa etc. comes to mind.
I contacted PFA engineering. They said the Flightstar is not approved or on the PFA register, so will have to do the following. This is what they said:
1.4.1 Type acceptance fee of £2000
This is charged to the manufacturer or UK agent which imports the example presented for PFA acceptance. The charge is triggered after the “Initial Aircraft Type Evaluation” (per E.P.12.). If the conclusion of this evaluation is that PFA Engineering is to proceed with the type acceptance process, this advised together with an invitation to provide this payment in order to proceed. In cases where the manufacturer or agent declares an unwillingness to provide this payment, it falls to the first UK builder of the type to meet this shortfall.
1.4.2 A Project registration royalty of £50
This is charged to the manufacturer or UK agent upon registration of the project. If neither of these can be identified then the charge must be borne by the person registering the project.
2.0 What Information Will I Need to Provide to the PFA?
The PFA will require a data package consisting of a descriptive data, definition of the design code and compliance data showing how the aircraft complies with the stated code.
2.1 Design Code (Certification Basis)
In order to qualify for a Permit to Fly, the design must generally be in accordance with the set of requirements (design code) which would be applicable if it were a fully certified aircraft. Some areas of non-compliance may be accepted if it can be shown that the feature either demonstrates equivalent safety to the requirement, or that there is a long history of the feature being used on similar types of aircraft in the past without causing airworthiness problems.