The cost is significantly higher than a normal cut and polish and wax job for 2 main reasons:
1) If being done professionally, the product being used is usually of higher quality and much more expensive to obtain and usually should be coming with a warranty as well.
2) Professionally grade coatings tend to be quite finnicky as they bond more permanently so specific training and a degree of specialisation is required to ensure the correct high gloss finish is achieved. When someone is offering their services very close to what a quality cut and polish is priced at with others, you will want to really check their products and quality of service very thoroughly.