You have really good skills in HTML/CSS/PHP/MYSQL ?
There is 2 steps in this work
- INITIAL DEVELOPMENT
You have to develop the interface, and the back office. According to the psd file.
You have to work with an API.
When the website is online. There are always bug to fix, things to improve and new functionnalities and tools to develop.
So, this is a long term relation.
The initial development will have a set price.
The maintenance will be hourly.
I you agree, so, maybe we can talk about it.
All the best.