To the extent feasible, this subchapter shall be construed so that the tuition charge for a pupil shall:
(1) Include any unusual costs associated with the pupil.
(2) Exclude any costs associated with the pupil which are paid from a source other than tuition and property taxes.
(3) Cover only the period during which services were actually provided or available to the pupil.
(4) Not impose a financial burden on the agency of service.