diff --git a/tests/test_main/test_config_selector.py b/tests/test_main/test_config_selector.py
new file mode 100644
index 000000000..36b2bf5a8
--- /dev/null
+++ b/tests/test_main/test_config_selector.py
@@ -0,0 +1,101 @@
+from __future__ import annotations
+import pytest
+
+from ConfigSpace import ConfigurationSpace, Configuration, Float
+import numpy as np
+
+from smac.runhistory.dataclasses import TrialValue
+from smac.acquisition.function.confidence_bound import LCB
+from smac.initial_design.random_design import RandomInitialDesign
+from smac import BlackBoxFacade, HyperparameterOptimizationFacade, Scenario
+from smac.main.config_selector import ConfigSelector
+from smac.main import config_selector
+
+
+def test_estimated_config_values_are_trained_by_models(rosenbrock):
+    scenario = Scenario(rosenbrock.configspace, n_trials=100, n_workers=2, deterministic=True)
+    smac = BlackBoxFacade(
+        scenario,
+        rosenbrock.train,  # We pass the target function here
+        overwrite=True,  # Overrides any previous results that are found that are inconsistent with the meta-data
+        config_selector=ConfigSelector(
+            scenario=scenario,
+            retrain_after=1,
+            batch_sampling_estimation_strategy='no_estimate'
+        ),
+        initial_design=BlackBoxFacade.get_initial_design(scenario=scenario, n_configs=5),
+        acquisition_function=LCB()  # this ensures that we can record the number of data in the acquisition function
+    )
+    # we first initialize multiple configurations as the starting points
+
+    n_data_in_acq_func = 5
+    for _ in range(n_data_in_acq_func):
+        info = smac.ask()  # we need the seed from the configuration
+
+        cost = rosenbrock.train(info.config, seed=info.seed, budget=info.budget, instance=info.instance)
+        value = TrialValue(cost=cost, time=0.5)
+
+        smac.tell(info, value)
+
+    # for naive approach, no point configuration values is hallucinate
+    all_asked_infos = []
+    for i in range(3):
+        all_asked_infos.append(smac.ask())
+        assert smac._acquisition_function._num_data == n_data_in_acq_func
+
+    # each time when we provide a new running configuration, we can estimate the configuration values for new
+    # suggestions and use this information to retrain our model. Hence, each time a new point is asked, we should
+    # have _num_data +1 for LCB model
+
+    n_data_in_acq_func += 3
+    for estimate_strategy in ['CL_max', 'CL_min', 'CL_mean', 'kriging_believer', 'sample']:
+        smac._config_selector._batch_sampling_estimation_strategy = estimate_strategy
+        for i in range(3):
+            all_asked_infos.append(smac.ask())
+            assert smac._acquisition_function._num_data == n_data_in_acq_func
+            n_data_in_acq_func += 1
+
+    for info in all_asked_infos:
+        value = TrialValue(cost=rosenbrock.train(info.config, instance=info.instance, seed=info.seed), )
+        smac.tell(info=info, value=value)
+
+    # now we recover to the vanilla approach, in this case, all the evaluations are exact evaluations, the number of
+    # data in the runhistory should not increase
+    _ = smac.ask()
+    assert smac._acquisition_function._num_data == n_data_in_acq_func
+
+
+@pytest.mark.parametrize("estimation_strategy", ['CL_max', 'CL_min', 'CL_mean', 'kriging_believer', 'sample'])
+def test_batch_estimation_methods(rosenbrock, estimation_strategy):
+    config_space = rosenbrock.configspace
+    scenario = Scenario(config_space, n_trials=100, n_workers=2, deterministic=True)
+    config_selector = ConfigSelector(
+        scenario=scenario,
+        retrain_after=1,
+        batch_sampling_estimation_strategy=estimation_strategy
+    )
+    model = BlackBoxFacade.get_model(scenario=scenario)
+    X_evaluated = config_space.sample_configuration(5)
+    y_train = np.asarray([rosenbrock.train(x) for x in X_evaluated])
+    x_train = np.asarray([x.get_array() for x in X_evaluated])
+
+    model.train(x_train, y_train)
+
+    X_running = np.asarray([x.get_array() for x in config_space.sample_configuration(3)])
+    config_selector._model = model
+
+    estimations = config_selector.estimate_running_config_costs(
+        X_running, y_train, estimation_strategy=estimation_strategy,
+    )
+    if estimation_strategy == 'CL_max':
+        assert (estimations == y_train.max()).all()
+    elif estimation_strategy == 'CL_min':
+        assert (estimations == y_train.min()).all()
+    elif estimation_strategy == 'CL_mean':
+        assert (estimations == y_train.mean()).all()
+    else:
+        if estimation_strategy == 'kriging_believer':
+            assert np.allclose(model.predict_marginalized(X_running)[0], estimations)
+        else:
+            # for sampling strategy, we simply check if the shape of the two results are the same
+            assert np.equal(estimations.shape, (3, 1)).all()