What doesn't sound safe?
A newbie with only 7 other posts and recently offering to buy 20 bitcoins with reversible payment methods, is now posting looking sell 25 bitcoins for irreversible payment methods?
Then another newbie with only 6 other posts shows up in the same thread claiming to have recently made a $2300 purchase from him via cash deposit?
What does sound safe?
If he's willing to send first, then its dangerous for him (very likely a scammer will try to take advantage of him).
If he requires the buyer to deposit the cash first, then there is a significant risk to any newbie that doesn't understand the risks of such transactions.
I'm not saying he's an untrustworthy guy, just that neither he, nor the person vouching for him have much reputation here, and if history is any indication there are a lot of warning signs here.