Yes, as a pet groomer, you can charge different rates for different shampoo services. Different shampoos may have different levels of quality, effectiveness, or ingredients, which can justify a higher price point.
To upsell the service, you can highlight the benefits of the higher-end shampoos to your clients. For example, you could explain how a premium oatmeal-based shampoo can soothe and moisturize their pet's skin, or how a hypoallergenic shampoo can help prevent allergic reactions. You could also emphasize the long-term savings of using a higher-end shampoo, as it may result in fewer visits to the groomer or vet for skin or coat issues.
Another way to upsell shampoo services is by creating package deals or offering bundled services. For example, you could offer a discounted rate for a shampoo and conditioning treatment, or a "spa day" package that includes a luxurious shampoo, conditioning treatment, nail trim, and brush-out. By packaging your services, you can incentivize clients to upgrade their service and try out different shampoos.