I recently bought a cheap Doogee X7 from DealExtreme to use as a GPS on the CTX200. After a few weeks of testing, I’m 100% satisfied with it. Great battery life, and a very bright clear screen – even through the cheap and nasty zip pouch mount that I’m using. I’m running the Doogee X7 without a sim card, and using offline maps with OSMAnd and RMaps.
Total cost: $115 for the Doogee X7, and $10 for the pouch/mount, including delivery.