add a little bench file -- "pytest tests/bench_empty.py --durations=10" will tell you how much overhead there is

python/tests/bench_test_setup.py

@@ -0,0 +1,18 @@
+"""
+run with:
+
+     pytest -vv --durations=10 bench_empty.py
+
+to see timings of test setups.
+"""
+
+import pytest
+
+
+class TestEmpty:
+    def test_prepare_setup_measurings(self, acfactory):
+        acfactory.get_many_online_accounts(5)
+
+    @pytest.mark.parametrize("num", range(0, 5))
+    def test_setup_online_accounts(self, acfactory, num):
+        acfactory.get_many_online_accounts(num)