DE_Patches.xml

    <!-- [WD] Simple Concrete by Wemd -->
    <Operation Class="PatchOperationFindMod">
        <success>Always</success>
        <mods>
            <li>[WD] Simple Concrete</li>
        </mods>
        <match Class="PatchOperationReplace">
        <xpath>/Defs/ThingDef[defName="TBarrier"]/costList</xpath>
            <value>
            <costList>
                <WDBlocksConcrete>3</WDBlocksConcrete>
                <Steel>3</Steel>
            </costList>
            </value>
        </match>
    </Operation>