@Triton: I'm not a huge fan of Endrek Sahr, Master Breeder because it does not generate immediate advantage, requires other cards to support it, and is inefficiently costed. The main problem with the efficient options is that they are fairly expensive monetary-wise (~$10). You have a majority of the low monetary cost efficient token generators, with that in mind my suggestions are Grave Titan; Bitterblossom; Master of the Wild Hunt; Kalitas, Traitor of Ghet; and Freyalise, Llanowar's Fury. All of the aforementioned are fantastic and probably deserve a spot here, but the real question is which/how many of these fit in your budget. There is also Avenger of Zendikar, but I'll let you decide whether this is a viable include because it's usefulness is based upon the amount of lands you have and stax isn't exactly know for its land prowess or ability to pump out 7 cmc cards effectively. Nonetheless tell me which of these, if any, fit in your budget and I'll help you make room.

On another note two cards I think should be in here as well are Bojuka Bog (graveyard hate) and Beastmaster Ascension (an additional win-con).

JaceTheSwagSculptor Okay, I'll add him in for the time being, but I intend on probably swapping him out if I can find a token producer for cheaper that is more better. I think Beastmaster Ascension will fit in wonderfully, and I know exactly what to take out for it already. I'll swap out a tapland for Bojuka Bog (easily fixed). Thanks once again for the input!

NP. Sorry I couldn't be of more help. I was looking at all the budget options and you pretty much have the efficient ones. However you do have some cards that are similar in cost monetary-wise to Grave Titan (~$6-7), so if you're able to afford it then the titan will definitely put in some work. Otherwise hopefully some better stuff gets printed in Amonkhet!

JaceTheSwagSculptor All good haha, I really appreciate your input so it's all good. :) I think I could try trading a card I already have in the deck for Grave Titan, which would be Living Death since it has never really helped me in testing since usually my opponents benefit more off of it.

I agree with that swap. Your creature package isn't too impressive so the payoff from Living Death is marginal. I would like to see Endrek Sahr, Master Breeder get replaced eventually as well. If you end up taking out Living Death, you may want one board wipe though just as a fail safe. Your best option without a doubt being Toxic Deluge.

I definitely agree with Toxic Deluge replacing Living Death. In a few weeks, depending how I feel, I may splurge and buy a Grave Titan and Toxic Deluge. I know I can possibly trade for one of the two.

I am building a Mazirek with very similiar budget and target power-level as yours. Therefore, your deck is a great help! +1!
PS: I've noticed that you're running Sifter of Skulls, yet Pawn of Ulamog is missing even though he is almost strictly better.