You can get a Moto G (same devices used on Webpagetest) anywhere from $84 USD (https://www.amazon.com/Motorola-Moto-1st-Generation-Unlocked/dp/B00GWR36F6/ref=sr_1_6?s=wireless&ie=UTF8&qid=1499457364&sr=1-6&keywords=Moto%2BG&th=1) to the "latest" editon for $229 w/out amazons bloat ware :) https://www.amazon.com/Moto-Plus-5th-Generation-Lockscreen/dp/B01N5MEKSW/ref=sr_1_1?s=wireless&ie=UTF8&qid=1499457364&sr=1-1&keywords=Moto%2BG&th=1
I mention these because I don't know if you can instal chrome on a fire table (couldn't a while back when I looked without doing sideloading google play)
If you want to get a new phone (as opposed to something used or refurbished), the Moto G5 Plus is coming out in 2 days. You can pick up the 32GB version for $230, or even cheaper if you have Amazon prime and are ok with lockscreen ads.