XML Feed making DB 2000MB Hosting Complaint

Hi
I am developing a new site and using wordpress. I have included an xml property into the database so they show as posts but my hosting company has just come back to me saying that the DB size is larger than the 500MB limit over 2000 MB and that we should move to dedicated/virtual hosting

Is there any way of reducing this bar removing certain countries or limiting posts to those 30 days or earlier?

Is this normal? Are there any other people running a large property db with wordpress that have had to confront this issue

Your help would be most appreciated thanks