I favor Amazon customer reviews over minimum wage sales guy. Like Dutchmen I went through a few cheaper routers before spending about $150. I do not attribute buying so many of those cheaper ones to just being inexpensive, they were poorly rated based on performance and reliability!
Please realize that for any given price point, there are limitations. Speed, number of wifi connections at once, range, etc.
Here are Amazon's tops sellers. Pick the one in your budget in the top 20 and you'll be pleased.
Here are the top rated, but not all are routers.
As mentioned, that CAT5 cable would go into the WAN port on the new router. That will likely have 4 more CAT5 wired ports as well as wireless configurations available.