Merge / Filter / Sort multiple .csv files

I need an application written that will take multiple . ---------- spreadsheets and merge them together based on a common field. It also needs to be able to filter and sort the output file into a .csv
I will be able to email you input .csv and an example output .csv file upon hearing back from you.
I will need a quote for the project. There will be additional apps needed similar to this on an ongoing basis.