I am new to Zoho community. I want to set up CRM for a client. The client is a Beauty salon. We want to use Professional plan. 

SO they sell services and not products. But at the same time, they use some products for these services and they would like to track inventory. 

Does anybody know how could I set up Zoho to function like this:

- When we sell a service we can also add products that have been used with quantity they were used. And then that should reflect our inventory. For one service there could be 1 or more products used. Plus I need to keep in mind financial aspect of this - product should have their price and services should have their price as well. Number of products used should not reflect the price. 

Easiest example would be a Massage. 

Customer comes for an 1 hour long massage. 

We spend 100ml of oil on that massage. 

In CRM we have service "Back massage" that we defined as 30 minutes for $X. 

I want to add to CRM that -100ml which costs $Y. And also put that we sold 2x30min back massage which is 2 x $X. 

$Y != $X. And there's no standard commission rate which we could add to get this X from Y. Because for one person we could use 100ml for that massage and for another it could be only $50 depending on their skin. 

I know it seems ridiculous to measure how much oil we spent, but it was the easiest example I could think of. 

I know that I cannot create custom modules. But I was wondering whether I could change existing module to fit my needs and how. For me the best idea would be to to add in sales order/invoice services and products separately, but I don't think I can add any module to act like products within sales orders/invoice.

Thank you!!

Cheers,

Iva