ONIX for Books 3.0 - XML to CSV Converter OR SQL script

I require a skilled freelancer to help convert ONIX for Books 3.0 XML files either:-
- into CSV format for importing into a SQL database; or
- directly into a SQL table
The zipped files are downloaded to local PC via MFT.

Key Requirements:
- Extract ALL data fields including:
- Title and author details
- Pricing and availability
- Full product descriptions and categories
- etc.
- Ensure all information from ONIX is captured

Inputs & Outputs
Inputs
- XML 3.0 Additions file - (lists new products) - file name format = nnnnn.add(N)
- XML 3.0 Update file - (lists changes to existing products) - file name format = nnnnn.upd(N)
- XML 3.0 Deletions file - (lists ISBN's no longer available) - file name format = 'nnnnn.del(N)
Outputs
- Separate CSV files for each of the above with naming convention nnnnn.xxx(N) OR:
- SQL scripts importing directly into separate database tables eg. additons, updates, deletions

Ideal candidate expertise:
- Proficient in data conversion and manipulation
- Experience with ONIX 3.0 standard and book industry data preferable
- Attention to detail for accurate data representation
- Knowledgeable in database structures to support seamless migration

Efficiency and accuracy are paramount.
Please highlight relevant experience with ONIX and data processing in your bid.