I'm afraid 1/10 is the best you can get on us to qualify for Final, but remembering last years semi v St Johnstone, that may be the safest bet. St Mirren are 6/1 to reach the Final.
1st Scorer is usually worth a look, especially if you have a clue of the starting XI. As we haven't had the most likely first scorers recently, maybe a wee punt on some outsiders is worth a flutter. Steven Smith is 33/1 (extrabet), Christian Dailly is 40/1 with stanjames, and Maurice Edu is 20's with bet365. More likely though are Boyd (7/2 at betfred), Miller (9/2 also betfred) or Velicka (9/2 at the same firm).
HT-FT is better odds than the match betting. Rangers-Rangers is a tempting 5/6 with Bluesq, Draw-Rangers is 7/2 with tote. St Mirren-Rangers is 33/1 at victorchandler, draw-draw is 15/2 with victorchandler.
Correct score is always a difficult one. If you like this, maybe a wee salvo of 3 or 4 likely results. 1-0 is 13/2 (vc), 2-0 is 6/1 (ladbrokes), 3-0 is 8/1 (bluesq) and 3-1 is 12/1(sky). 4 bets that would return a profit if one came up.
As it's played to a finish there are market you don't always get in ordinary matches. BlueSq and 888 are both offering a "method of victory" market. They go 1/3 Rangers in 90 (ignore that and take the 4/11 to win the match), 7/1 the Gers in extra time, or 16/1 a penalty shootout win. St Mirren are 9/1 for a 90 minute win (again, ignore it), 20/1 to win in extra time, and 50/1 to win a shootout.
There is another semi on Sunday, not that anyone outside Dunfermline or Falkirk will notice. Wm Hills are biggest on the SPL side (maybe not for much longer) winning at 23/20. expekt are best for a draw at 23/10, and Sky offer the Fifers at 3/1.
However you go, good luck, well, good luck if you're betting on any kind of Rangers win!