The quality of condition monitoring (CM) is an important factor that directly affects the effectiveness of a condition-based maintenance (CBM) program. While numerous works in the literature have considered problems related to CM quality, few of them focus on adjusting CM quality for CBM optimization. In this paper, assuming that the quality of CM information can be controlled by adjusting inspection costs, we investigate how such an adjustment can help to reduce the total cost of a CBM program. The CM quality is characterized by the variance of the system degradation information returned by an inspection. Normally, a more accurate CM information requires a more sophisticated inspection, hence a higher cost. An inspection and replacement strategy adapted to such a variance is proposed and formulated based on Partially Observable Markov Decision Processes (POMDP). The use and advantages of the proposed joint inspection and maintenance model is numerically discussed and compared to a more classical one through numerical examples.