The main driver of my comment is that I purchased 3-year terms before Amazon introduced the various categories of utilization. My instances have to run 24/7, s

The main driver of my comment is that I purchased 3-year terms before Amazon introduced the various categories of utilization. My instances have to run 24/7, so I need "heavy" utilization instances with concommitant higher hourly savings. By purchasing 3-year RI's prior to the utilization categories, I paid more (350 vs 300) for the reservation than even the costliest new reservation type (heavy) but my hourly rate is higher ($.06 vs $.059) than even the costliest new hourly type (light). At this point I can't run the numbers, though, b/c I'm not sure how much a 1-year term would have cost me back then. I only know how much I did pay for my 3 year terms. Maybe my gripe is simply that I feel my pre-category RIs should have been converted to "high" RIs with better hourly rates =)