Asus announced the next-generation Zenfone 2 — one of the first devices to boast 4GB RAM — at CES earlier this year, and now the device is up for pre-order in Chinese retailer Alibaba's marketplace AliExpress. There are two variants of the device available for choosing: a version with 2GB RAM that is priced at $299, and the 4GB model, which is on pre-order for $439.