You are correct that their are plenty 146-300's kicking around, some still from BUZZ.
Actually, after last week's deal with LH for 11 146-300s, there aren't many 146-300s available at all. All the buzz are now spoken for. What's left on the market include three ex-EI stored in the desert (still on lease to EI; they decided to withdraw them from use long before their leases expired) and the ex-Ansett ones stored in Australia. That's pretty much it.