The profile itself is free. Google does not charge to claim, verify, or maintain a Google Business Profile. Any service that charges for the profile itself is reselling something you can access directly at no cost.
Where Community Proud adds value is in setup and optimization: selecting the correct primary and secondary categories, writing keyword-relevant descriptions, uploading quality photos in the right formats, configuring services and products, setting up Q&A responses, and enabling messaging. A properly optimized profile performs significantly better than a basic one. Optimization is a one-time engagement with optional ongoing management.