We are in the middle of 2012 udpates and we are thinking of doing the following:
Migrating to SQL Server 2008 from 2005 (i have read this will give us a small speed boost)
Increasing memory from 8GB to 32Gb (we were having some memory pressure and time out issues..) ($600)
Buying a SAN (dell md3000), for HA reasons, but also becuase I read it will help speed up the application. (this is a 6K investment...)
Replacing our 4 year old Dell 2950 with new R510 dual processor with 32gb ram. (4K for a new server)
Which one of these actions above will give us the most bang for the buck? Which one should we do first?