Mirror Blank

Anyone know a source for a LOW COST mirror blank? I'm looking for 16-20".

Have porthole's gone way of the Dodo's? I can't seem to find anything!

Another possibility is maybe I'm just too cheap!! I know about inflation - but glass shouldn't go at the same rate as oil should it?

Any advice will be appreciated!
thanks,
Dom

Dom...My friend bought a blank from Newport Glass in Stanton Calif and also had it rough ground to f-4.5. He paid 700 for it.
I don't know if that's too much for you....they also coat mirrors. His came out great...16" f-4.5. We tested it against a 16" f-4.3 Zambuto on Jupiter with both scopes using TV 7mm Naglers. No big difference could be seen. Zambuto with a VERY slight edge after going back and forth about 4-5 times. Gerry