This game doesn't even exist in Betfair-land, but is indeed happening tonight rather than Sunday as some students have priority over full-time Sheffield for the pitch.
Anyway most games between these 2 are normally pretty close, interspersed with the occasional massacre by Halifax. Despite Sheffield going full time, they don't seem to me to have improved their squad at all from last season, whereas Halifax have, and have also perhaps spent their cash winnings a bit more wisely on conditioning and analysis services. Sheffield were very lucky IMO to beat Halifax in the play-offs at the end of last season.
Anyway I find it hard to separate the sides, and make this a scratch game, so the beteveryday offer of 13/8 Halifax looks pretty attractive if you can get on.