AD,K
TURNTURNTURN
What self-respecting dungeon would be without traps or monsters? And what better way to fulfil both requirements than kobolds? Well, there are probably a bunch, to be honest, but this is the best within your price range.
With a minor fanfare in the form of arcane sparks and a cloud of blue dust, dozens of kobolds materialise in the shallower reaches of your corridor. Short, reptilian humanoids, pre-equipped with crude pickaxes, shabbily dressed in vaguely-clothing-shaped rags. Unperturbed by being thrust into existence, they split into small groups, with some headed outside to forage for food and supplies. The remainder you direct to assist in the creation of traps- though they may look stupid, sound stupid, and be stupid, kobolds are remarkably skilled at trap-making.
With kobolds helping out, traps are quickly established along the length of the corridor leading up to the spinning maze. There are spikes that emerge from the walls, spikes that emerge from the floor, spikes that swing around corners... there's a certain spikey theme. Okay, not the most inspired, and the tripwires and pressure plates are not exceptionally hard to notice and disarm, and even if they trigger, the average adventurer is not going to be killed- but they certainly add a little variety.
Time passes. The kobolds keep themselves fed (although technically they can subsist on dungeon prana, actual food is more filling, improving performance), and build up stockpiles of wood, furs, and shiny rocks- what passes for treasure amongst kobolds. They also maintain the traps- again, not technically necessary, but it improves performance. Unfortunately, no adventurers arrive. Two weeks after the last party left, you begin to wonder if they've forgotten about you. You could try doing more to lure in adventurers, perhaps?
A: Send kobolds further afield to attack humans.
B: Make the kobolds build ominous totems throughout the surroundings.
C: Have patience; you're not in a rush.
To help keep track of things, I'm adding a Status spoiler:
ENERGY RESERVE: Very Low
KILL COUNT: 0
REPUTATION: Barely Known
DUNGEON DETAILS
LAYOUT (Applies to entire dungeon due to fractal nature): Corners & Alcoves.
ENTRY: Modest but intriguing.
FIRST SEGMENT:
Inhabited By: Matt, Kobolds
Traps: Spikey
Features: None
SECOND SEGMENT:
Inhabited By: Kobolds
Traps: Spikey
Features: Spinning Maze
FURTHER SEGMENTS: Unexplored and unmodified.