non-parallel walls or diffusion for tracking room sound

Hi everyone, this is my first post. i'm in the very early planning stages of putting together a studio in a bottom basement of building in Martha's Vineyard, mass. This space has a total room area of around 2500 cu/ft, ten foot ceilings and concrete with 4 feet of concrete seperating the ceiling from upstairs floor. I come from the school of playing and producing music more than studio construction. So my terminalogy could definitely be wrong in a lot of ways here. What i'm trying to figure out is what is the best way to plan this space out with a budget of no more than $40-$60 thousand for everthing. One wall was built at a 110 degree angle but all so only two of four angles are at 90 degrees. Whats left is cutting out a corner of this room for a control room. From what i've gathered (mostly out of Alton Everest's Master Handbook of Acoustics) non-parallel walls don't really work as well as putting up diffusers to get a more flat (across the frequency spectrum) but not dead sound. I would like to here some opinions on this because I at first was sort of thinking to go with more non parallel walls like maybe a 3 wall shape out of the corner for the control room. But after what i've read it seems like this just causes more hotspots with dips and peaks at different modes around the room in unusual places. thanks alot. finding this board was great.

That budget is tight, but doable with DIY and simple (read inexpensive unless done by self/friends) finishes. With a room that small (250 ft^2) diffusion is not really significant because there is not enough space for the room sound to develop. Focus on absorption and angles of reflective surfaces. Andre