that's a lot of money to spend just to get a quill stem.

you're looking at:

fork: $75-125
headset: $30-50
stem: $25-60
labor: $30-60

total: $160-295

if you know how to do the labor (or a friend does), you could do it much cheaper.

find a used fork for $50, stem for $20, get a headset from nashbar or elsewhere for $30 and do the labor yourself.