That's cause you are looking at the wrong ones. This is the one that lasts for fricking ever. You can order it with a PVC casing and either a pot controller or advanced controller with 0-5V input for about $300 and they are guaranteed to last 20,000 hours at continuous duty or they will replace it. Cole Palmers are definitely a better pump, but I would rather get one of these for $300 than spend $1500 on a comparable cole palmer that will last 40,000 hours.
http://aptinstruments.com/pdf/SP200VOBLPS.pdf