Most designer bags are great quality. What you're paying for is the name. There is absolutely nothing wrong with that, just be aware of it. The quality doesn't get exponentially better as the price rises. (And ignore the people who don't think bags are "worth it." Personally I don't think new cars, sports tickets, or Star Wars memorabilia is "worth it". Judgement like this just mean it's not something I, personally, want so therefore if I bought it it would be a waste of money.)
I like Dior bags personally. The lamb skin is butter soft and the patent holds up spectacularly well. I've carried a patent tote for years, I'm not at all precious with it, and it still looks brand new. For far less expensive brands I like Kate Spade, which isn't as market saturated as Coach. There's some lesser known brands, such as Linna Pelle, that also make beautiful bags.