I'm very suspicious about the 1st one: Exselle goes for over $1000 new, so $150 for the brand new saddle sounds very very strange (EVEN for eBay).
Don't know about 2nd saddle, but 3rd one (Collegiate) is a nice brand and price looks right, however it doesn't look forward enough, so if you plan on jumping and have long legs I'd keep looking.
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