Per Watt generated they use more resources. Again, per Watt generated, not overall. Most large scale plants generate GWs of power with each core being close to a full GW or more, where SMBs are in the low hundreds of MWs. Larger plants are able to leverage their scale to reduce resources for the secondary and support items, like the power distribution or large scale cooling systems, the later get significantly cheaper and less resource intensive with larger size. So it does costs more for the whole (large) site, but when you break the cost down per Watt of generated power, larger sites will tend to be cheaper to both build and operate.

SMRs do potentially have additional safety features though, so it's possible operational costs might be less. But material costs won't be smaller, you still need containment system, turbines, transformers sub-stations, etc. They'll be smaller because there's less load, but when you scale that up to the same output of a large plant, you'll need more resources for the same power output.

I'm not trying to knock SMRs. A single plant is cheaper to build, but it also generates significantly less power then a larger unit, with many of the same design and zoning constraints.