10K vs 15k rpm for analytics

Anyone has any experience doing analytics with postgres. In particular if
10K rpm drives are good enough vs using 15K rpm, over 24 drives. Price
difference is $3,000.

Rarely ever have more than 2 or 3 connections to the machine.

So far from what I have seen throughput is more important than TPS for the
queries we do. Usually we end up doing sequential scans to do
summaries/aggregates.