There are a few stories of failures from Nikon refurbished here, but I've always had good luck with Nikon. Their customer service isn't what it used to be, and every repair seems to be $350-450 these days.
I have always had positive experiences with Nikon USA refurb. I think I have purchased 2 bodies (one DSLR, one Z) and 6 lenses (4 F-mount, 2 Z). I had an issue with one lens, noticed it right away, contatce them within 48 hours of receipt - authorized the return and the shipping, and had a replacement within a week, which was just fine.
MPB has them with a six month warranty.
MPB (or KEH) is a whole 'nother deal than an Amazon refurb offer where one has any idea who actually did the refurb...or if one does, it ends up being a 3rd party that is a non-authorized reseller who doesn't have access to Nikon parts that may be needed for a proper refurb. MPB (and KEH) y'know what u are getting, and they back it up. With a solid warranty that is DEFINITELY better than Nikon's refurb warranties.
The savings could cover a third party warranty. You can buy them through Amazon or directly, and they are generally better than a new Nikon warranty anyway.
Is this for repairs, or replacement? Asking because I honestly don't know. If it is for repair -- why would one trust a 3rd party reseller that just sent a faulty refurb lens, maybe/maybe not gray market, to do the repair if they are not a Nikon authorized servicer/seller? If it is for replacement - maybe -- as long as it isn't gray market, or do they try to play the old "Abe's of Maine" game ...
Amazon has a subscription warranty program that might work well for some, if they read the fine print.
Dunno about that, never heard of it. Would be interested in reading the fine print. Having said that... saving a couple of bucks in this manner, YMMV (I don't think it does I think u are just pointing out options here) IMHO is just not a good way to go these days.
Camera bodies and lenses are just too expensive to try to shave a few bucks off here and there. There's ways to save money here and there by going thru reputable used gear places like KEH and MPB, or thru Nikon Refurb. Rather than rolling the dice and taking a chance.