Kevin It would appear that some people have muscled in so to speak and will produce a sort of demo but not only do they want to be paid for this they want the credit and any royalties as well. My attitude is avoid these sharks like the plague.

If you want a good studio and musicians with no strings then see Sub. I also have contacts who operate the same way he does.
As far as costs are concerned then it is down to how much you want to invest in your music and what you think it is worth. It might be a tad more expensive than a flat rate bog standard demo BUT it will be better quality customised to suit you and YOUR PROPERTY.
I can understand why some people mainly amateur hobbyists would use a demo service but serious musicians avoid them like the plague.

http://www.soundclick.com/bands/songInfo.cfm?bandID=687727&songID=5238055