Walmart offers the Mainstays Twin-Over-Twin Wooden Bunk Beds
model no. WM3921, in four colors (Cherry pictured) for $159.88
. Shipping adds $14.97
, or opt for free Site-to-Store. Even with shipping, that's $14 below the lowest total price we could find for a similar bed elsewhere. Sales tax is added where applicable. These beds can also be used unstacked. They feature a wood slat system intended for coil-spring mattresses.