I think Sandmans problem with regard to budgetting is that it was never intended to be a TV series, and the way they're being almost slavishly faithful to the source material means there's not a lot of budget trimming they can do, other than hire unknowns for the cast or have CW level SFX.
Assuming similar treatment to S1, S2 introduces the rest of the endless, revisits Hell, introduces (at the least) the Norse, Egyptian and Shinto pantheons, would likely introduce and foreshadow the Faerie, and cover the consequences of the dead roaming the earth, ending with the appearance of Abrahamic angels.
And thats the first half of the season. the Second half is entirely Never Ending Story, with (again) mostly all new characters, all new sets and locations, and heavily CG driven.
There's really not a lot of opportunity to do a couple of bottle episodes to stretch the budget.