Most chromebooks don’t come with whole lot of on board storage since Chrome OS is mainly in the cloud. If you are like me and sometimes have to work offline, a large MicroSD card goes a long way to improve that.
Sandisk largest MicroSD card is now on sale for a price that almost as good as the deal they ran on Black Friday. The 400GB A1 can be ordered from Amazon for $89. It has read speeds of 100MB/s, and should more than double the storage of most chromebooks.
They also have a sale on the 400GB A2 for $150. The A2 has read speeds of 160MB/s but unless you do a lot of 4K Video transferring this the A1 should be more than enough and a much cheaper price.