You're correct, argitoth, you will still see a considerable boost to search speeds with a properly built index. This especially holds true if you have any mechanical hard drives in your system (which is very likely). I wouldn't worry too much about the search index either way. The amount of writes you would save is fairly negligible, but the search performance would still suffer.
If nothing else, simply moving it to another drive is still a great solution. You don't have to worry about extra drive wear at all then, and you still get blazing fast searches.