CPT

can you make the xml for the Extended have the rounds info

<Item Name="" Descriptionidentifier="smg45_magazine_noff" identifier="pistol45_magazine_noff" variantof="pistol45_magazine" maxstacksize="1" Scale="0.45" category="weapon" subcategory="Ammunition" allowsellingwhenbroken="true" cargocontaineridentifier="metalcrate" tags="smallitem,pistol45mm_magazine,smgammo,45_ammo,magazine" impactsoundtag="magimpact" health="8">
        <Price baseprice="18" soldeverywhere="false" buyingpricemultiplier="2">
            <Price storeidentifier="merchantoutpost" multiplier="1.3" minavailable="4" />
            <Price storeidentifier="merchantcity" multiplier="1.25" minavailable="5" />
            <Price storeidentifier="merchantresearch" multiplier="1.25" minavailable="2" />
            <Price storeidentifier="merchantarmory" multiplier="0.9" minavailable="8" />
            <Price storeidentifier="merchantmine" multiplier="1.25" minavailable="4" />
            <Price storeidentifier="merchantmilitary" multiplier="0.9" minavailable="4" />
        </Price>
        <Deconstruct time="10">
            <Item identifier="45_round_noff" amount="4" />
        </Deconstruct>
        <Fabricate suitablefabricators="milfabricator" requiredtime="10" >
            <RequiredSkill identifier="weapons" level="50" />
            <RequiredItem identifier="45_round_noff" amount="8" />
            <RequiredItem identifier="titanium" />
        </Fabricate>
        <InventoryIcon texture="%ModDir%/Img/ammo.png" depth="0.551" sourcerect="459,670,64,64" origin="0.5,0.45" />
        <ItemContainer hideitems="true" capacity="100" drawinventory="false" canbeselected="false" ShowConditionInContainedStateIndicator="true" SpawnWithId="45_round_noff" removecontaineditemsondeconstruct="false" containedstateindicatorstyle="bullet">
            <Containable items="45_round_noff" />
            <StatusEffect type="OnUse" target="This" condition="-1" disabledeltatime="true">
                <SpawnItem identifiers="45_round_noff" spawnposition="ThisInventory" />
            </StatusEffect>
        </ItemContainer>
    </Item>

this isnt 9mm but 45, so things will be different but you can see how its done

replace titanium with steel and

check the amount of rounds in the mag, then check the round cost, in noff its 13, so do (roundcost) x (health) + 30 = baseprice for new mag
health is the amount of rounds, it cannot be edited, its a read only
health isnt something that should ever be changed as thats a read only

if identifier="pistol9mm_magazine_extended_noff" and Descriptionidentifier="pistol9mm_magazine_extended_noff"  are the same, dont have a Descriptionidentifier

Descriptionidentifier inherits the description of the identifier in its text, so having them the same is redundant

 it needs the ItemContainer and InventoryIcon still needed