Cacti Graphing incorrect load averages

cacti has a bad default graph which stacks the 3 values from load average. The total is meaningless, and that is what you are deceived into looking at. Change the default graph to use lines rather than stack and you'll see something better.

Bear in mind that load (e.g. /proc/loadavg) can be averaged on different intervals (tipically 1, 5 and 15 minutes). Add the fact that averaging these figures once again over a time series tends to lower the overall indicator, and you may have a hard time making your case for getting an upgrade.

I suggest you stop thinking on a technical solution and start building a business case around a different indicator, preferrably one that has a correlation to an economic or customer satisfaction indicator -- e.g. maximum response time. Most likely this will get your message through to the people that manages the money.