I am trying to find a single source (a feed like XML or RSS, or
anything else that can be parsed and categorized by a script without
too much trouble) that shows comparative odds data for sports betting
across several online sportsbooks (at least 10-20, but more if
possible).

I don't mind paying for access to this data, but I need to be able to
use the data for commercial purposes, and it needs to be current and
reliable.  It should also be at a reasonable price (no more than $10
per month for every sportsbook it has data for, so a source that shows
data for 20 sportsbooks shouldn't cost more than $200 per month).

I have searched the net for this information, and have come up short. 
Several sites claim to have such feeds available, but are unresponsive
to emails.  The answer to this question must be a source that actually
has this type of technology, and is willing to sell access to the data
(or make a deal of some sort in exchange for it).

Traditional comparative odds sites like BetBrain.com cannot be
spidered for this information, as their terms prohibit commercial use
of their data.

If you have any questions, please let me know.

Thanks everyone for your help!

covers.com has this sort of thing...it may no tbe in the form you
want, but they haave about 10 books listed and it hi-lites the best
home and away bets