Search Best Buy's website for the model CB5-132T-C8ZW and it's on sale right now (Lucky You) for $259
I checked the reviews on this Chromebook at websites CNET PCMAG and LAPTOPMAG and all of the versions of this laptop had the 4 GB RAM
The professional reviewers mentioned both Best Buy and Costco as having the 4 GB and I verified it on both websites.
I also went to ACERs website and it showed BEST BUY one of the online sellers that had 4 GB and ACER's website also had a series of check boxes for options
This model ACER CB5 had both options 2 GB (Amazon's version) and 4 GB (Best Buy)
Some of the Amazon reviewers are complaining about performance issues, and I'd bet it's due to the RAM being only 2 GB on Amazon's model.
(Sure I'd rather have 8 GB but that isn't an option with this one)
I bought mine w 4 GB from Best Buy online and am happy with it so far. I have this as a backup to my only other pc which is a Windows 7 Desktop (with ClassicShell installed)
To find other sellers, do an internet search for ACER CB5 132T C1SY 2-IN-1 TOUCH SCREEN CHROMEBOOK QUADCORE 4GB MEMORY