I've seen people on there talking about how sometimes it helps to trim the stock shorter when installing the limbsaver so the length of pull remains the same.
The Limbsaver is thicker than the factory pad. So, if you wanted to keep the same LOP, you'd have to shorten the stock. I have never had this done, so any price quote would be a WAG (Wild A$$ Guess). I do have a friend who had his stock bent for about $100; I would think that shortening one would be much easier and cheaper, probably somewhere from $35-65. Again, that is a WAG, and would not include shipping if you don't have a local 'smith you can trust to do it right.
HOWEVER - if the pad fits the stock perfectly before it's cut, then it almost certainly WON'T fit the stock after it's cut.
In my case, shortening the stock could possibly make the stock's dimensions closer to the pad's; but,
1) I'm not sure how much I'd have to take off
2) I'd actually prefer to increase the LOP
Others who have installed the pad also appreciate the added length, but that's a decision best made on an individual basis.