We purchased a 7.2 TB P4300 Starter SAN (HP Part# BK716A) and we're now looking to expand our storage by adding a third node into the SAN (the original configuration came with two nodes). We asked our vendor for a quote for a third node and we're surprised at the cost; essentially the third node with 3.6 TB of storage costs as much as the entire 7.2 TB SAN ($20k). The part number we were quoted on for the third node was BK718A.
Is this the correct part to add additional storage onto our SAN? If so, shouldn't it be around half the cost of the full 7.2 TB SAN we bought? If the pricing is correct, why wouldn't we just by another full 7.2 TB SAN and get double the storage for the same price? Any insight into how expanding a P4300 works/is priced would be appreciated. Thanks.