diff --git a/src/worker/director.rs b/src/worker/director.rs
index 9c1ae93..f56a8b7 100644
--- a/src/worker/director.rs
+++ b/src/worker/director.rs
@@ -910,35 +910,38 @@ impl DirectorWorker {
             return Ok(());
         }
 
-    // compute piece price and full sell price
-    let piece_price = Self::compute_piece_sell_price(item);
-    
-        let one_piece_cost = Self::resolve_one_piece_cost(conn, item.product_id, item.sell_cost)?;
-        let cumulative_tax_percent = Self::get_cumulative_tax_percent(conn, item.branch_id, item.user_id)?;
+        // compute piece price and full sell price
+        let piece_price = Self::compute_piece_sell_price(item);
+        let revenue = piece_price * item.quantity as f64;
+
+        let one_piece_cost = Self::resolve_one_piece_cost(conn, item.product_id, item.sell_cost)?;
+        let cumulative_tax_percent =
+            Self::get_cumulative_tax_percent(conn, item.branch_id, item.user_id)?;
 
-        // Preis-Inflation: Der Preis wird basierend auf der Steuer inflatiert,
-        // damit der Netto-Betrag für den Verkäufer gleich bleibt (wie im Frontend)
-        let inflation_factor = if cumulative_tax_percent >= 100.0 {
-            1.0
-        } else {
-            1.0 / (1.0 - cumulative_tax_percent / 100.0)
-        };
-        let adjusted_price_per_unit = (piece_price * inflation_factor * 100.0).round() / 100.0;
-        let revenue = adjusted_price_per_unit * item.quantity as f64;
-        
-        // Steuer wird auf Revenue berechnet (nicht auf Profit), wie im Frontend
         let revenue_cents = (revenue * 100.0).round() as i64;
-        let tax_cents = ((revenue * cumulative_tax_percent / 100.0) * 100.0).round() as i64;
-        let payout_cents = revenue_cents - tax_cents;
-        
         let cost = one_piece_cost * item.quantity as f64;
-        let profit_cents = revenue_cents - (cost * 100.0).round() as i64;
+        let cost_cents = (cost * 100.0).round() as i64;
+        let profit_cents = (revenue_cents - cost_cents).max(0);
+
+        // Steuer wird vom Gewinn abgezogen (nicht „zugerechnet“)
+        let tax_cents = ((profit_cents as f64) * cumulative_tax_percent / 100.0).round() as i64;
+        let payout_cents = revenue_cents - tax_cents;
 
         eprintln!("[DirectorWorker] sell: revenue={:.2}, cost={:.2}, profit_cents={}, tax%={:.2}, tax_cents={}, payout_cents={}", revenue, cost, profit_cents, cumulative_tax_percent, tax_cents, payout_cents);
 
+        // Treasury-User-ID optional per ENV, fallback auf DEFAULT_TREASURY_USER_ID
+        let treasury_user_id: i32 = std::env::var("TREASURY_FALUKANT_USER_ID")
+            .ok()
+            .and_then(|v| v.parse::<i32>().ok())
+            .unwrap_or(DEFAULT_TREASURY_USER_ID);
+
         if tax_cents > 0 {
             let tax_amount = (tax_cents as f64) / 100.0;
-            if let Err(err) = self.base.change_falukant_user_money(DEFAULT_TREASURY_USER_ID, tax_amount, &format!("tax from sale product {}", item.product_id)) {
+            if let Err(err) = self.base.change_falukant_user_money(
+                treasury_user_id,
+                tax_amount,
+                &format!("tax from sale product {}", item.product_id),
+            ) {
                 eprintln!("[DirectorWorker] Fehler bei change_falukant_user_money (tax): {err}");
             }
         }