Questão jurídica principal
Whether the exercise of previously granted purchase rights triggers the cantonal real estate transfer tax.
Decisão extraída
Yes. Under cantonal practice, the tax is due upon exercise or transfer of the purchase right, not already upon its grant.
Fundamentação extraída
A purchase right transfers significant disposal power, but taxing its grant would unduly restrict the federal civil-law institute. To avoid excessive interference with federal law, the canton taxes the right only when exercised or assigned to a third party.