I don't tend to get jealous about stuff, but I do get jealous about experiences, mainly travel. Some friends of mine took off for a 2 week trip to Europe, and I was drooling over the pictures. Another couple recently went to Bora Bora. More drooling. Another friend is a serious world traveler. She lives and works in various exotic locales, and travels to other ones constantly - right now it's Morocco.
However, I know the first couple very well, and they take out loans/use credit cards for everything. As much as I'd love a 2 week trip to Europe, I prefer our weekend trip to Canada, with everything paid for out of pocket. And frankly, we could pay out of pocket for a europe trip too, but it would impact our budget in ways I don't want it to. Plane tickets alone to Bora Bora would be $4K. Again, we COULD do it, but we have other plans for that money. While the world traveler does well financially, she has said that she's given up on having a family because it's too hard to meet guys and maintain a relationship with her job. Those aren't trade-offs I'd be willing to make.
I'm also a horseless horse person. I own an unrideable retired horse who lives half a country away, and that sucks up all my discretionary money. When friends post pictures of their weekend trail ride, or horsepacking trip, I do get a big twinge of jealousy. I really miss being able to do that. Again though, I COULD own another horse. We could afford it. It would have a big impact on what we're saving though, and assuring our future is more important to me than riding right now. It's not like I really have time at the moment anyway, between 2 jobs, school, and 2 toddlers.
Things like fancy clothes, cars, electronics, jewelry, and purses though - meh. I've never gotten my hair done by a professional except for a couple weddings I was in. I've always cut my own hair, and always cooked at home. I live in yoga pants or jeans at home and scrubs at work. I still wear some t-shirts that I got in high school.