Just a few things to consider, if you spent $300+ on PM7, what kind of complimnet is a $30 - $50 outdated solution going to provide for you? Most everything that these older versions could offer, will most likely be included in some form or another of PM7.
Depending on what you are doing with the Corel programs, and what functionality you are trying to get out of it, you may have to check the version first, For example, RAVE is only available in version 10.
I may be mistaken, but isn't version 11 for the MAC only? If there is a PC version, then as is typical, within a few months, older copies of 10 should start going on sale. If you are looking for use on a MAC platform, you will have a lot more limited price options - most of them will be expensive.
Also, if you do some searching online you will find some OEM versions of Corel. Most of these are for installs with new systems, and not meant for resale incividually, yet people still sell them. They are fully licensable versions, but you have to deal with the ethical and legal aspects of such purchases. Otherwise, just do a search on google for "Corel Draw retail". Also check
and
You probably won't find an OEM version for MAC.
Russell