Interdependence between first and second moments of producer and consumer wheat prices in Slovenia is assessed. A joint estimation of a threshold vector error and MGARCH models with exogenous variables in the conditional mean and conditional covariance equations are applied for such purpose. Results indicate that price-level adjustments mainly favor retailers by increasing their marketing margins. Important second-moment interactions are also identified. Increases in international wheat stocks reduce producer prices, while higher interest rates increase their instability.