buying vintage online

i was scoping a few new (to me) blogs and ended up on a shop called nasty girl. after looking around a bit, i came across this vintage dress for $98. the kicker: i have the same one in my closet. i found it at goodwill a few years ago for under $10. i totally win. while we are on the topic of folks selling vintage online, can i ask - are the prices of vintage clothing getting outrageous these days, or is it just me? i mean, like i said. i found the exact same dress for 90% less. this isn't the first time that i have seen the same dresses and clothing that i have in my closet being sold online or at etsy for a what seems like a super pricey mark-up. but maybe it is just me that feels this way, because people are seeming to buy vintage dresses for $60 and $70. i guess i'll just have to stick to goodwill. it hasn't seemed to fail me yet.