Until, unless I am not getting the details, I am unable to commit you any estimated time. May be many freelancers have already mention that they will be able to complete this project with in few hours as you mentioned. But I am interested to know the details- Regarding XML feed, I need to know the exact details.- Please let me know which types of feeds you needed- will it be for content types, for users, for Nodes, for taxonomy terms or any other?
Also I need to check your existing website or source code. It may that you have some issue to share the source files. On that case, you can share your screen as well. I will check the files over team viewer. - Please confirm me which be convenient for you. I will move accordingly.
Generic Solution: I can use Feeds module for XML feed. This module Import or aggregate data as nodes, users, taxonomy terms or simple database records. It import CSV files, OPML files, RSS/Atom feeds etc. By this module, I can import large files using batch processing. This module create nodes, users, taxonomy terms or simple database records from import. Also extensible to import any other kind of content.
Also you can go for Feeds Xpath Parser module as well.
Please confirm me which one be convenient for you. I will work accordingly.
Already I have worked with XML import to multiple content types project. If you need details of project, I will share with you. There are lot's of points to discuss before awarding the project. Please have a chat.