Well Kid, this is a very important and often debated topic.
A pair of mics that sounds similar is critical for recording an orchestra of for that matter, any stereo source. However, personally, I find that too much emphasis is placed on exact stereo matching. Many mics are so carefully designed and built, that even over disparate serial numbers, consistant sound and quality are still the norm. Schoeps is definitely one of the companies that is on the forefront of this quality control and critical build control.
Personally, I don't see that there would be any issue with you doing this whatsoever. I would tend to think that you are better off doing this than to spend less money on inferior microphones just because you can afford them right now. That being said, there are microphones within the pricerange of a single Schoeps that would give you rather good quality and the ability to purchase in pairs (matched or not).
In summary - feel free to buy the single Schoeps and feel confident in your ability to find a close mate for it soon in the future.