P’Tham ka.
I think you should do proper proposal for K.Jeed to approve. It must be in presentation (power point) format. The detail should include;
Points you need to consider;
1. What is your rational of proposing the price? Why 20% across all menu?
2. Did you do market analysis/research (area/customer type/customer spending)?
3. Direct and indirect Competitors pricing within and outside our category (3-5 star hotels/Bill Bentley/local Thai restaurants at different areas where they can charge higher price/Kallaprapruek/Grey Hound)?
4. Pricing for lunch, dinner set, special occasion menu? (insert/artwork)
5. Your new pricing should support the objective of driving sales, beverage and spending
There are a lot more opportunities that you need to explore, this is the only one opportunity we have because everything has its costs.
Please consider ka.