I'm going to only address 3 categories for buyer's remorse today. I know there are many out there and I'm counting on you to add your own examples.
Exercise equipment: didn't that fancy treadmill sound like a good idea at the time? You were going to walk every day, adding on the miles as time went by and then you'd enter your first big race/walk.
So, how'd that go for ya? Did it become just another place to drape clothing?
And let us not forget the full set of weights in the basement that promised to make you look like Arnold. Gathering dust are they?
Kitchen appliances: the blender that was going to do everything except the hand jive. After using it once and finding out was a pain in the ass it was to clean - is it now sitting way, way in the back of some closet/pantry?
Clothing: the shoes that really weren't you but you were trying to "step outside the box" you've been living in for too long and bought them anyway. And you paid top dollar for those suckers. And they hurt your feet!
I can't possibly be the only person out there who has gone astray.
Misery loves company - let's hear it!