There are a couple of stores online which I've perused a lot, but purchased from infrequently, if at all. That could be due to price, or due to the practicality of the items I was looking at. I'm sure we all have places like this.
American Science and Surplus is a store I've made purchases from. I regret missing the boat when they had wall padding (y'know, for your very own padded room!), but we've got such assorted wonderful items from them as plastic minis for D&D monsters, a stand with a magnifying glass and little calipers to hold things (for painting), stainless mini funnels for hip flasks, and those mylar survival blankets. Their prices are typically cheap, which makes the shopping all the more attractive. They have spy pens. And look they have big foam dice! I'm sure they're still too small to let the dog use, though.
I'd love to buy stuff from J. Peterman one day, but they're super pricey. I LOVE how their product descriptions are frequently short stories or flash fiction in their own right (like for Georgina's Sunset Polka Dot Dress), and they evoke a kind of Breakfast at Tiffany's Monte Carlo Golden Age of Hollywood kind of glamor in my mind. It's good stuff. And who wouldn't want a long velvet blazer for her hypothetical author tour? I definitely want one.
I like Etsy because you can find all sorts of random shit there, and I've made select Etsy purchases over the years. A dog treat bag and jewelry have been my primary purchases, and a stuffed toy for a friend who just had a kiddo. It's where I've gotten my rosary bracelets (I broke the first one and am too clums/lazy to fix it), and man, I'd love to find a religious medal of St. Christopher cynocephalus, but I'm not sure that'll ever happen. I also intend to buy a flask that says "Holy Water" on it one of these days.
And apparently I'm a crazy shoe person, so Fluevogs get perused occasionally (these are great. And these). I'm really hesitant to buy shoes online, though, because sizing is so weird sometimes. I also really need sandals I can wear to work for when the weather warms up, as I said "Okay, I can't keep wearing these" and threw out my old ones in a cleaning fit. And I'm still yearning for Tieks, obviously. Though I'd probably get black ones because I get black everything.