Are there any tools to view previous prices for Nike shoes?

So I was looking at these blue Nike Dunks on a few different websites because I finally saved up enough money from my summer job at the car wash to get a nice pair for the new school year. I have like 160 dollars total to spend including shipping and stuff but the prices keep moving around and it makes no sense to me. One day they are 110 and then the next they are 145 and I feel like I am going crazy or maybe the website is just tricking me?? I dont really know how any of this works since I usually just buy whatever is on sale at the mall but these are special and I really want them to last.

Is there a way to actually see what the price used to be last month or even last week? Like a tracker or a chart or something so I can tell if today is a good day to buy them or if I should wait. I saw some people online talking about resale and retail and honestly it is super confusing to me and I have no idea where to start. I just want to know if I am paying too much right now because I dont want to waste my savings if they are gonna go back down tomorrow. Sorry if this is a really basic thing that everyone already knows but I am totally lost on where to look for this kind of info or if a website like that even exists...