After reflecting a bit, my original answer failed to account for hard-to-find items. Now that all types of product shortages are becoming common, I have to be honest about how this affects my decisions. I can normally resist over-paying simply because other people are in a mad rush to buy guns, but I will raise the price I am willing to pay for something that I am really interested in, especially if I worry that I may not find it again.
This usually hits me with used guns that I had always wanted when they were new, or when I was younger, but never got around to buying. It can also hit me when a gun I never quite got around to purchasing is discontinued. I never fall for the "I need another AR now before they are banned" hysteria, but I can convince myself to pay more if I think I won't be easily able to find a certain model in the future.
This urge is what initially turned me on to Springfield. I bought a 4" .45 ACP XD Mod.2 on an insane clearance when the Mod.2 line was discontinued. It wasn't even on my radar, but I didn't have any double-stack .45 ACP handguns and the price was barely half of the original MSRP. I loved that gun and spent the next couple months tracking down a 9mm version for almost $100 more than I paid for the .45. I don't regret the purchase, but I wish I had bought the 9mm when they were being cleared-out a few months earlier.