diff --git a/tools/budget.go b/tools/budget.go
index 4e9a6c2..f71f1ae 100644
--- a/tools/budget.go
+++ b/tools/budget.go
@@ -87,11 +87,15 @@ func (l *budgetLedger) committedUSD() float64 {
 
 // purchaseSpent reports whether a purchase that reached PurchaseCommitment
 // must stay counted. Only a clean no-op (nil error, no success, no error) or
-// an adopted existing commitment is released; every error and any other
+// an adopted existing commitment returned with no error is released; every
+// error (err or result.Error), including one returned beside ExistingCommitment, and any other
 // result may have spent money, so it stays counted.
 func purchaseSpent(result common.PurchaseResult, err error) bool {
+	if err != nil || result.Error != nil {
+		return true
+	}
 	if result.ExistingCommitment {
 		return false
 	}
-	return err != nil || result.Success || result.Error != nil
+	return result.Success
 }
diff --git a/tools/budget_test.go b/tools/budget_test.go
index c5f4a96..71ab036 100644
--- a/tools/budget_test.go
+++ b/tools/budget_test.go
@@ -2,6 +2,7 @@ package tools
 
 import (
 	"context"
+	"errors"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -114,6 +115,20 @@ func TestBudgetExistingCommitmentReleases(t *testing.T) {
 	require.NoError(t, runWithNonce(fake, "a"))
 }
 
+func TestBudgetExistingCommitmentWithErrorStaysCounted(t *testing.T) {
+	resetBudget(t, "100")
+	fake := pricedFake(60, common.PurchaseResult{ExistingCommitment: true}, errors.New("boom"))
+	require.Error(t, runWithNonce(fake, "a"))
+	assert.InDelta(t, 60, processBudget.committedUSD(), 1e-9)
+}
+
+func TestBudgetExistingCommitmentWithResultErrorStaysCounted(t *testing.T) {
+	resetBudget(t, "100")
+	fake := pricedFake(60, common.PurchaseResult{ExistingCommitment: true, Error: errors.New("boom")}, nil)
+	_ = runWithNonce(fake, "a")
+	assert.InDelta(t, 60, processBudget.committedUSD(), 1e-9)
+}
+
 func TestBudgetUnsetRefusesBeforeResolve(t *testing.T) {
 	resetBudget(t, "")
 	fake := &fakeServiceClient{}