Continued DTS Support With What SQL Server Version/Edition

We currently have access to another department's SQL server.  However they are taking that server offline within a few months, and we will need to migrate our data and DTS packages to a new solution before then.  We have about 30 databases and 20 somewhat simple DTS packages, but only a few users need access.  Funding is very tight.

SQL 2005's support of DTS is somewhat of a mystery to me.  Docs state with 2000 Enterprise client tools installed + Express edition, that I can run DTS packages on Express edition.  But the docs do not state the procedure for doing so, and I cannot register the Express server in the Enterprise manager(states must be using 2005 version of Enterprise manager).  It seems I can Design a DTS package that resides on the 2000 server and specify a connection to the Express server, but the DTS package would not run, stating always that the table was in use, and I haven't explored it any further.  May have just been a quirk. 

I'm trying to conquer this in two pieces:

Cheapest solution for graphical design of DTS packages, or some techniology similar(I think I understand that this is called SSIS in 2005?).  This would be needed by 1-4 users.

SQL 2005 Developer Edition for each user, only about $50 per user.
MSDE for each user, but can this house DTS packages and be connected to by enterprise manager?
Cheapest solution for data access and ability to run DTS packages by 2-10 users.

If SQL Express Edition is used to house data, can the DTS packages be distributed in some way that allows the users to run them?  I.E. exported as VB code or some sort of file that can be loaded by an Access 2002 or VB.NET frontend.
Can all users have Developer Edition or Desktop edition and run the DTS package from it, but have the DTS package connect to the Express Edition server where the data is housed?  Or would this be a violation of what the Developer Edition is intended to be used for?
Any other suggested scenarios are welcome.

Are we allowed to continue using the 2000 Enterprise manager after we no longer have access to a licensed SQL 2000 Enterprise server?

The feature comparison for the different 2005 editions doesn't mention DTS, but I know it works for some editions if the add on components are installed.  I'm just not sure which versions support this.