if you want a stock maple shaft then mcdurmott is probably the cheapest and most of their are 3/8 x 10
however if you want my vote on the best aftermarket shaft for any cue I would go for any of the OB cue lines to fit your type of game.
I have 2 of the OB-1's and 1 of the OB-2 and they are the best shafts I have ever owned.