If SD can't help you, your best bet at getting a reduced price is to talk to one of the people who got a "Free" extra copy due to mail errors or one of the very disgruntled people who want to return the game (likely to charge more, but since they only get 75% of the cost back less s&h)... good luck.
there's a lot you can "Edit" through modding and changing the xml files, since you can't pick what parts of the patches you want and don't want, your more likely to get better results through self/player edits. running off old patches sounds like more frustration then it would be worth, especially if you have to shell out $$ for it. spending a few hours, let alone a few days only to encounter a major crash would really suck.