Profiler for a Java application - Buy or Build ?

These days there are loads of Static Java code Analyzing tools and Java application Memory Profiling tools available in the market. Would you bet on buying it or building your own custom profiler tool ? I was just leaving over an article which explains how to build your own Java profiler. It explains some of the limitations of the existing profiling tools and explains how an ideal profiler should work and explains how to use aspect-oriented programming and the Java 5 agent interface to build your own profiler incorporating some of these ideal features.