You came to the right place.
I LOVE my MB 149,its the mother of all pens and I call it my queen.
Its a FANTASTIC writer.Its a pen that everytime you hold it in your hands it makes you want to write.
No doubt its a big pen so be sure it feels comfortable in your hand.
If I were you I'd wait to get it off the "Marketplace" and I wouldnt buy it new.You can get a 149 in excellent condition for 300$ or so.
I own few more MB pens some LE and lots of other fantistic pens but none makes me fell as my queen does-long live the queen

If you want to buy it ne w I'd try to contact Altman and FPH I believe there prices are very good.
I got all my new MB pens from the FPH.