Been creating my own -1 & +1 lines for many years now.
You will get a slightly better price than what the books offer
when you do it yourself. The key to this is creating these at
the low juice books.
Pinnacle
5Dimes
Heritage
Bet Online / Low Vig
Loose Lines
Creating these at your average book the price will not
be as good. Reduced juice shops are the key to this.