I am considering replacing mine, it's not in horrible shape but, it was painted poorly so it's started to flake a bit. The glass in one pane also cracked this spring. Finally, the sealant that they used to bed the glass (not a gasket) stains everything black. I have to compare the cost of repairing what I have to replacing it.
I bookmarked this place
http://www.americanmarine.com/index.html when some one else on this site suggested it.
If you find out a ball park price from this place or anywhere else, please share it.