Thanks busman,
The price is not my main concern, I am more worried about all the extra problems with going to 4" that will affect the quality of the product. The only real reason I want to go to 4" is to be able to do a reflux run of 45L of low wines in fuck all time, but if people are getting over 5L an hour in hearts with a 3" thats got to be better than what I am running now.