Amazon is selling a Mellanox Connectx-4 Mcx4111a-acat 25gigabit Ethernet Card - Pci Express 3.0 X8 - 1 Port(s) - Optical Fiber for $102.31 which is a very good price for this card. They indicate they have four in stock.
Here is the Mellanox Store page Mellanox MCX4111A-ACAT ConnectX-4 Lx EN Network Interface Card 25GbE Single-Port SFP28 PCIe3.0 x8 ROHS R6I bought one and the price immediately increased to $281.80, more expensive than the $260 it is at the Mellanox store.
FYI - MCX4111A-ACAT is SFP28, as zkrr01 stated, not *Q*SFP28 (which is used for 50/100 G). The picture does show QSFP28 but I presume that's just an error.
Good to know. Thanks!I bought the single unit sold for $102. The vendor was Amazon.com itself. See the pricing history here which shows their dynamic pricing in action where it probes the market by decreasing the price until one sells then raising it back up again. It got as low as $63!
I bought an expensive Supermicro chassis last year which was nearly half normal price after I watched the price steadily decrease for months until I thought it was bottoming out. It's almost as fun as Ebay auctions 15 years ago!
Amazon.com is also selling the MCX515A-CCAT but they haven't moved the price yet - here. You can set up price tracking on camelcamelcamel for any Amazon product.