So I hesitated to show this deal based on the interesting commentary and PM's that developed from the last one, but I actually ordered from this person and I've got a set of these tweeters in my ride, so I can vouch that this is legit.
Pair 2pcs Alpine HiEnd 28mm Dome Neo Magnet XT25 Tweeter 4ohm 50W | eBay
He's in China so don't expect them tomorrow morning, but I ordered a set and got them 14 days later so it isn't bad. The price, however, is amazing and they are legit Alpine SPX PRO tweeters. The package is literally just the tweeters, so absolutely no mounting equipment is included. You must create a very precise mounting hole to make these work, but here's an example of success, in my Durango (modified factory location):
Anyway, I ordered an extra two sets after this successful purchase, so I've got enough for myself, for now. If you need a good set of tweeters that can play somewhere in the 3k range and up (maybe lower with aggressive crossovers and reduced power), these may be for you.