I have a Google nexus 5 which is fairly cheap, and really well specced for its age and a huawai mediatab tablet which I was given for free when I took home broadband out.
As mentioned, if your game runs an a lower spec device, it'll run on better devices. (I always develop and devices wither a lower spec than my target device.)
It's best to have as many devices as you can, with different screen sizes etc. I've found that it's the screen resolutions that cause the biggest issues rather than device spec. (So far, i've not had a game that won't run on a lower spec device! I even ran my VR Zelda game on my Galaxy Gear 1 smart watch!)