This is a common scam. It's incredibly popular on forums where tens of thousands of people gather to buy-sell-trade gear.
Typically, this is how it goes:
1.) Someone posts on a forum "I want to buy something, anyone have any?"
2.) A scammer acting as a friendly reader PMs you "I think John Doe had some for sale and his email is
scam@youdamnedfool.org"
3.) The recipient's scam-detector doesn't go off because the first contact wasn't "pushing" anything on you. Further, you do the reaching out to the email of the referred seller so your brain forgets that it wasn't you contacting them in the first place. It's actually a psychological technique magicians use all the time "forcing a card" where you think you're in control and making choices when you're not.
Behind the scenes, the scammer was able to target you for something that you already said you wanted via PM, but you didn't report it as scam on the PM system because its just a friendly reader giving you a tip. Once he gets you off the PM system and onto an unmonitored email, he has his way with you.
I tried to buy a specific kind of bow press on another forum and posted WTB and got several of these types of scam replies. As dangerous as the web is for scams, I have to say AH is the very safest forum to buy or sell something online. The circles in our area of interest are small, the reputations are established, and usually buyer and seller want to have a phone call to get to know each other better to consummate a sale. Scammers don't want to chat about safaris but folks here do! When in doubt, pick up the phone!