Why do you want those particular brands/models, tho?
The B&W model isn't too old and the price on these when they were new is pretty expensive, much more than the Monitor Audio B2. So I suppose they're not budget speakers, unlike the B2's.
Why the B2's - mainly reviews, I don't have a place to audition them as I wrote which is a bummer, but they seem to fit my needs. Also, they're described as bright, and I suppose using a subwoofer will balance it somewhat. The B&W's I looked at are bass heavy as I understood.
So it's either a secondhand expensive speaker for the same price of the B2, or a new pair of B2's - which are budget speakers.
I'm leaning towards the B2's for the bright sound but I honestly can't check them anywhere, and I barely have time to audition the secondhand one's. I mean I can, but I'll have nothing to compare them to...
Generally, are B&W's worth the money? I'm afraid they'll be too bass heavy considering my subwoofer, but also don't want to pass on this deal, if they are indeed worth the money and are better than most budget speakers.. I mean the price gap is noticeable between both models when new, around three times the B2's, at least here in Israel...