Need some help

It would be a lot of work, but if you can't FIND any appropriately sized barbed wire, perhaps you could make some. I have found wire like "Florist's wire" or "Craft Wire" can look right in a variety of sizes, and the hard part would only be finding the correct gauge of wire to look like barbed. Without having a handy cross reference, I have used 5 strands of 26 gauge braided to simulate a wire belt for a Hulk figure before, and though it's not barbed wire, there are a few ways you could make it look like t, possibly as simple as tying knots in the wire at the correct length.

Like I said to you in IM bro

Pipe Cleaners might be the cheapest and safest bet

Burn all the fluff off them, clean off soot and use - works a treat

You could try to use wire or those twist ties.

Try a hobby store with like trains and stuff.