Just as free of charge as 7.3!!! that is: 7.3 is NOT free of charge!

And XE actually is free of charge, provided you run it on a single
processor machine, with less than 1GB memory for Oracle, and less than
4GB of database!

Would you not reconsider your choice for 7.3?

Frank van Bortel

PS: When for non-production (study, development), every version
actually is free to use - read the developers licence on the download
page of otn.oracle.com.