I used a TomTom years ago and really liked it. When I moved back to Canada, I didn't have access to a computer and Staples was pushing Garmin, so I bought a decent-looking unit for $170 ($$). I was only planning to use its voice navigation to steer by, but the damned thing didn't speak much nor give nearly enough lead time before turns. I gave it to my brother to try and he punted it to his girlfriend after one roadtrip. It's on its way to becoming a doorstop.
My brother told me to use Google Maps on my phone, so I bought a battery upgrade kit for $80 ($) and replaced the old one. Made no difference at all. Battery life on the first-gen Moto G simply sucks. I use an old wi-fi only phone plan from my old US carrier, since it works here and only costs $10/mo. Without continuous data, I had to download the maps onto my phone. That's when I found out there's not enough storage on the phone. So much for that. If I upgrade the phone ($$$$), they charge more for the US plan ($$). And Canadian plans can best be described as $$$$$ (serious lack of free market here).
Next, I researched both GPS brands and found the TomTom GO 600 to be very highly rated, so I bought it for $300 ($$$$). It includes lane change guidance and warns you if you go over the posted speed limit (a must in a city filled with 24x7 30 km/h playground zones). After lots of trial and error, I finally got it installed on the far left of the dashboard, where it doesn't block my view. It remains to be seen how well the suction cup sticks to the mounting disk that you glue to the dashboard. That 3M glue is wicked! A better adapter and extra mounting disks for my next car ($BLING) run about $.
I wish I had bought the 5" model instead of the 6" as the latter is bulky when wrestling it out of the dash's corner. The unit is detailed enough that you can see entire stretches of major highways and exits on the screen well before you reach them (think Queens Long Island Expressway, but with fewer idiots). A quick glance at the screen and a few voice prompts ever km or so, and I'm all set. Now I'm ready to visit my doctor and grocery store 2 km away. 
All total, about $600, which is a sizeable hunk of change. Still, the cost of a basic speeding ticket in a playground zone is about $300, not including the increase to your insurance rate. God forbid you lose your license in a city this sprawling. No Uber yet (soon), so taxis across town cost $$$$.