Inverter Vs Econo

I need to replace two bedroom air-conditioners, both rooms need 9000 BTU models.

I've read many times that the Inverter technology is good and does save a pile in electricity.

But this week I started checking prices and discovered that Inverter is very expensive indeed.

Then I noticed Econo technology, which is much cheaper.

But gotta be honest I can't find any write ups on Econo.

Comments and suggestions very welcome and appreciated.