Your search for "C4KX-NM-8SFP+" revealed the following:
NEW Cisco C4KX-NM-8SFP+ Catalyst 4500-X 8x 10GB SFP+ Switch Module
SKU: NSN-2732
Condition: New
Shipping: Overnight Options
Warranty: 365 days
$ 199.99
• Only 1 remaining
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Cisco C4KX-NM-8SFP+ Catalyst 4500-X Series 8x 10GB SFP+ Switch Module
SKU: NSH-7346
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 62.99
• Only 2 remaining
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Cisco WS-C4500X-40X-ES 40x 10GB SFP+ Front-to-Back Airflow Switch
SKU: NSH-4668
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 223.99
• 11 in stock
Call if you need more
Cisco WS-C4500X-F-16SFP+ 16x 10GB SFP+ Back-to-Front Airflow Switch
SKU: NSH-4669
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days