EcoStar: $1149
Goldline AquaPLUS w/cell: $1290
Hayward C4025 SwimClear: $729
ThePoolCleaner: $469.50

That is about half of what you have. How did you get to $8k?

But if you want to go cheaper, I would at least get a lower HP two speed pump. The pump you chose is single speed and will not be very efficient. Also, I would strongly suggest going with the same manufacture for everything so you can get the extended warranty.