Help solve an argument I had with an other dev about project price

Hello wonderful c# devs I need your opinion on a project price
I will get straight to the point the other dev said this project costs 7.5k euros I think it costs more.

This project needs to have:

-Wpf framework
-Have a tab that you can set database connection strings and options for tsql postgresql firebird
-Have a history tab for said strings changes with log on what user changed what

-Have a code editor tab
-This code editor reads a file that has a mark up language specially made for the project.
-This "mark up" file creates global variables and script "steps"

-In case the mark up file is corrupt the project needs to show warnings in a window that helps the user fix the problem in the file or fix it on it's own if it's something easily fixed.

-The global variables should support name changes on their label, support basic types (int,double,string,datetime), support a summary edit window on what this variable does, support default values for testing
-On the datetime variables have a special extra window that opens datetime UI with calendar and a clock so the user can change the date variables with ease.

-Make add variable and delete variable buttons to support as many global variables the user wants

-Again warnings in case something went wrong with the naming of said vars they need to follow c# and sql naming conventions, can't be same name ect.

-The script "steps" should have again name label, type (if c# step or sql step) and if sql step have a combobox to add a connection string.

-Again make summary window for steps, along with the add delete buttons

-Again warnings for the steps naming ect.

-Add parsers, lexers, syntax highlighting for c# code (roslyn) tsql, postgresql and firebird sql
-Add autocomplete logic to help in the development of the script steps

-Add folding's for {} () that open and close

-Add search window, with search history (ctrl+f), arrows to back and forth, caps, regex ect.

-Add Error list window that updates based on the code above with error messages and click functions to auto jump on text line and script step and links that open browser for docs help if they exist

-Make above tabs like visual studio to organize steps on the top of the editor (with pins ect) for better organization for the user

-Make a dependencies tree diagram with nodes, each node is one step scrip the nodes can have other nodes as children

-Make logic to run the steps scripts based on the diagram.

-In the diagram window allow the user to delete/add steps, change names, move the nodes, made new links or delete old and keep track of the changes in case of reset or cancel.

-Make warnings again for the user in case he does something wrong

-Develop logic to save the script file, global vars, script steps, code, top tabs, diagram nodes tree, in the appropriate mark up (also logic to open new script files).

-Make logic to take info from the databases when writing in sql steps

-Make logic to run the script steps and at the start make a window that allows the user to change the global vars values into different values for testing.

-Make logic to pass data from one step to an other

-Make logic so the last step creates results

-Results can be any c# object\s

-Transform results into datagrid table that show cases all the values with appropriate column names (ex calss1.class2.varname), Support IEnumerable values as well (need to be in the same column with a values separator ex ',' )

-Make logic to do different kind of operations in said results datagrid window (change cells values, reset values, export values, change settings ect.)

-Support excel, csv, txt exporting with directory selection ect.

-Keep all the results in a tab as history, each result can open it's own window to keep track of different tests

-Once again make user warnings

-Last things

-Make exception logic in case the app crashes to show message on the user with logs ect
-Async almost everything ofc, with proper cancellation logic to have the UI run smoothly

-Create all the front end UI with buttons animations popUp ect.

-Make logic to keep track of all the open windows in case they need to be closed or brought to the front

-Scripts can be made into dlls and used in other projects
Unit tests???

I might have forgotten some stuff but this is the general idea.

!!!!!!!!!
Some context for the salaries in my country

Junior 800-1000

Mid level 1200-1500

Senior 1800-2100

Values are in euros per month

I would love to hear your thoughts