The same slab underneath, two extra steps on top
Everything below a stamped slab, the compacted stone base, the reinforcement, the mix, is the same work that goes under a plain broom finished slab. What changes happens on the surface, in the narrow window while the concrete is still soft enough to take a pattern. Color goes in first, then a release agent keeps the mats from grabbing the surface, then the mats go down in sequence and get tamped so the pattern seats to full depth. Edges and corners get hand worked with a flexible skin where a rigid mat cannot lie flat. None of that changes what the slab needs underneath it to hold up, and a crew that rushes the base to spend more time on the surface has the priorities backward.
Not the same finish as exposed aggregate
Stamped concrete and exposed aggregate get lumped together as the decorative options, but they are built by opposite methods. Stamped work presses a pattern into the surface and leaves the original cream layer on top, colored and textured. Exposed aggregate goes the other way, washing that cream layer off while the slab is green so the stone already in the mix shows through underneath. One adds a surface. The other removes one. They land in different price bands for the same reason, stamped work takes more hand labor and a tighter time window than a wash down does.
The upkeep that comes with the look
Stamped concrete needs sealer, and sealer is not optional the way it can be on a plain broom finish. The color lives in the top layer of the slab, and sealer is what protects that layer from traffic, weather and stains. Skip resealing long enough and the fix stops being a simple recoat and turns into stripping and rebuilding the surface. That upkeep is worth weighing against the look before you commit, not after the first winter, because the slab that gets a coat every couple of years is the one that still looks like stone a decade in, and the one that does not is the one people end up disappointed by.