The J&L expander plug for carbon forks weighs only 7g, saving up to 34 grams over a generic alloy expander plug. The minimal design resembles the Extralite expander, at a fraction of the cost. However, this design does not offer as much support as the generic plug. If you have a fork with an aluminum steerer, a star nut weights about $10, making this a poor value. If you are concerned about breaking your carbon steerer, this plug is not recommended. Consult the manufacturer if their fork requires an expander plug to reinforce the clamping area. At $13, and saving 2.6g per dollar, it represents a good value, moderate cost upgrade. It can be purchased on eBay.
Price: $13 [Moderate Cost]
Value: 2.6g/$ (0.38$/g) [Good Value]
Recommended with caveats
This expander does not offer as much structural support as a stock expander. Some manufacturers may require the carbon steerer be supported from the inside with a full length expander plug.