Please explain these steps in full details
How to write code for these lines .
Add empty cell prompt "Manually input prices if not selected"
Filter pick-list on estimatingMethod.pricing = true
On selection if quote.contractType <> null and edtimatingMethod.contractType <> null and quote.contractType is not IN list of estimatingMethod.contractType then give warning message "Contract type in CLIENT tab xxx does not match selected pricing strategy contract type YYY"
There are lots of fiddles that show how to do this stuff. Also the documentation. And the examples like the kitchen sink. This is not a "I am stuck on something" question. This is a please write my software.
Take a look at the store filter method. You fill a pick list with a store and filter it.
The placeholder property of a text field will show in an empty field.
Take a look at field validation in the examples for how to show a warning messages based on selections.
Link showing validation and also placeholder.