I suggest that there should be careerist skills for sale instead of guns when you get your daily CR/GP. The sale on careerist skills would either be added with the daily sale gun, or a daily sale gun would be on every other day. The sale for ONE careerist skill would be random, of course.
Small Suggestion: Some people (like me) are tired of leveling up. I suggest that you should add a button that gives you the next level automatically for GP. For example, if you're level 0, you need 100 GP to buy level 1. Level 1 -> Level 2 for 200 GP. Level 3 -> 300 GP. Level 60
-> 6000 GP etc. The price may sound expensive, but it's an automatic Level Up. Not like I'm going to spend x GP (x= my level multiplied by 100), but this could be helpful.
I kill a zombie with a backpack. He drops a machete and some cookies. What should I get, some cookies that give me health, or a machete that can help me survive? I take the cookies, of course.