Found the same thing. There are a few areas which let you stock up on balls quickly. Centennial park is suppose to be one but I found one by my one of my pleasure palaces.
Kitty corner the Subway beside Loco is a park with four Pokemon stops. Walk to one then to the red hut for another - on to the other corner , then around to the garden. It forms a 4 spot circle that takes a few minutes to circumnavigate at which time the timer is over and you can start again. I picked up 30+ balls in just a couple laps. I'm the same - I won't pay either.
Yup, Centennial is okay. I also go to West Deane Park on bike with a handle mount for the phone and sometimes go all the way downtown.
Having now play this for a few weeks I really like this game. Its getting me outside more, its getting me more connected to my kids and great exercise. The other day I did 30 km walking and am biking a lot now also. It's a lot of fun taking down a gym and seeing the reaction of the people on the outside trying to build up their levels and I just take out all their 4 players and put in a ridiculous low level player just to mock them and seeing their expression in real life and they never suspect it is me. Its also good for meeting women...the other day I took down a 4 level gym put my so so pokemon player and noticed someone take it out right away and put in a jigglytuf...like wtf...I noticed a girl in her 20s just chilling casually with her dog...so I took it out again and put my best player and noticed the girl started looking and you can see her thinking like wtf I just put my player and its already taken down...then she turns around and looks me straight in the eye and picks up its me and we connect with a smile ...lol...so I put on my strongest player and noticed her get all serious on her bench, sit up straight her dog just chilling and she gets her game face like its on bitch...lol...I was with my kid so I left with the car but she connected again as I was leaving turning her head and she gave me the "what a pussy" look becuase she was hoping to see my reaction to when she took me out again...lol...if I was not with my kid this could have been an awesome exchange with a hottie...
So now finally I am on level 20 and it's getting easy to take out 4 level gyms with 4 players with 2000 CP or less...the only thing that kind of sucks is that you need a team from your color to help you level up a gym once you take it down and I dont feel comfortable teaming up with real people yet.... AFIAK you cant put two of your players on one gym, unless I was doing something wrong. Also after this 20 level you get a lot of rare and high CP Pokémon to show up, you get the black balls that help you catch them and level them up higher.
The best part is seeing peoples reactions and communicating with them, your expressions, and you can play with with people and have fun with it. Its kind of a mental augmented connection thats kind of interesting to take part in.
I finally understand why the hype and its so much fun as its bringing gamplay and reality is this augmented reality thing and it is done so well. This looks to be the future of gaming.
also at night you notice some serious battles happening with hight school and college kids using very high level Pokémon such as 3300 CP. One hour you notice all gyms in one area red with ridiculous high CP Pokémon and then you check again like 3am and everything is back to team blue....lol...like turf wars.