Garmin, Tom Tom, HP, and which Model Should I Choose....I NEED HELP!!!!

Hi Everyone!

I have not been on AR in awhile and was just browsing Ebay looking at all the GPS systems that are available.  Being a Realtor I should know where every house is in the city and further (Not) so I occasionally still take that wrong turn.  I hate when that happens.  So to save embarrassment I thought I would purchase a GPS system for my car.  Okay!  Now I am overwhelmed.  I had no idea that there were so many companies, models, features, I think I am getting a head ache.  So I thought to myself I would reach out to my AR family and ask people who actually own one of these devices to please recommend a good one....and cheap would help too!  Mostly I need it for showing homes, so I will  need to be able to enter in multiple destinations and if the thing could tell me which way to turn would be great.  Thanks in advance and I look forward to reading your responses.  Oh, don't forget to tell me where it can be purchased either and any pitfalls to avoid would be greatly appreciated.