Advice ?

Looking to get back into collecting comics. I use to have a huge collection but when I grew up and moved out I needed a proper place to store them in my new home so I left that at my grandmothers for the time being and well let’s just say my little cousin who was probably 6 at the time had a field day with them and was coloring and cutting them to pieces. My fault in the end but I want to rebuild my collection! About to have my first son and would love to pass on my passions to him. Any advice on how to build a good collection without breaking the bank ? Huge Batman fan here