what are you hoping to get out of the frame slider? If you're going to let the bike fall with it on, one on ebay is going to protect the bike just as well as an expensive, name-brand one.
You can't skimp on most things, but frame sliders are gonna get scraped, and your bike will still get scraped nonetheless.
Frame sliders are not necessarily meant to protect your fairings, they're to protect the engine from receiving damage. The 250's fairings are designed to enclose the engine and to protect it from damage, rendering frame sliders somewhat pointless. Fairings aren't cheap, but these framesliders are. Framesliders will provide a little protection for the fairings though
framesliders are really for race bikes to help them "slide" on the track. If you slide on the road, with all the damage (cracks, potholes, etc) as well as other objects (curbs, medians, etc.) framesliders really don't help that much. If you drop your bike at a high speed, your bike's going to get damaged, and the last thing you'll worry about is your fairings, or your bike at all for that matter.
But they'll serve the purpose of low-speed fairing protection. So, again, I think those will work just fine