I've just recently started freelancing. I will do it for cheap for a short period of time, to build some portfolio here on freelancer.com. I have years of experience in music recording, production, mixing and have also worked on a couple of sound design projects.
Now, there are two ways I can recreate an instrumental for you:
One way is to remove the vocals from the original recording. That way the instrumental will sound the same as the original recording. The problem when removing vocals from a song is that, in some cases (differs from song to song), part of the instrumental can be affected as well. However, this can be done in a single day, and will therefore be cheap! In many cases, this approach works great. If this sounds good to you, I'll make a sample and send it to you for free. If you like it, you pay and get the whole thing!
The other way is that I recreate the entire song from scratch, record every instrument, apply mixing and mastering. This is a lot more time consuming (at least a weeks work), hence it's more expensive. It could sound better, but it will not sound like the original recording. I can get it to sound close, but not exactly the same.