Two shelves, same price range, completely different daily experience. A fixed under sink shelf holds more weight and costs less; a pull-out lets you reach the back of the cabinet without emptying the front. Which one you should buy comes down to how deep your cabinet is and what you store.
Fixed shelves: cheap, sturdy, and easy to outgrow
A fixed tier is fine if your cabinet is shallow, or if the items on it are things you grab from the front — a dish soap refill, a box of dishwasher tabs. The trouble starts at depth. Kitchen base cabinets often run 20 inches or more, and once you put a second row behind the first, you stop using it.
Pull-outs: the fix for depth and plumbing
A basket that slides toward you means the back row is as usable as the front, which effectively doubles what a deep cabinet holds. It matters even more with a P-trap, because you can't lean past the pipe to dig. The trade-off is a slightly smaller usable footprint and a weight limit — a pull-out isn't where a cast iron pan lives.
What about a lazy Susan?
People ask about turntables constantly, so: they work only if your cabinet is wide and the trap is centered high enough to leave a clear circle. Under most sinks the pipe eats the middle, which is exactly where a lazy Susan needs room. Tiered storage on either side of the plumbing uses that space better.
The setup we recommend
Two levels with pull-out baskets, split across the pipe. That's what the SinkFlex 2-Tier Pull-Out Under Sink Organizer ($33 for two units) is built to do — adjustable shelf height so it clears the trap, and baskets that slide out so the deep back of the cabinet earns its keep. Keep heavy or wet items on the cabinet floor beside it rather than on a basket.
Choose in one question
Is your cabinet deeper than your forearm can comfortably reach past the pipe? Then pull-out. If not, a fixed tier plus a no-drill door hanger ($23) is enough — or take the 3-Piece Bundle ($55) and get both.