Was looking for this specific Chromebook and noticed Amazon warehouse has "like new" units for $370 with 20% discount at checkout.
Final price came to 296.08 (plus tax)
That's $150 off regular price.
The also have Very Good for 349.54 with 20% which comes out to $279.63.
If you are looking for brand new, Best Buy has it on sale for $399 minus $25 edu coupon for $374. Not the cheapest, but the cheapest I could currently find for brand new.