There are a couple of things to tell you.
First, Google has declared that it has a problem with sales price. So far, we have customers with 100% sales price problems in the UK, and several customers who find that on a USA feed, the products that are individually displayed are showing sales price well, but that any product sucked into "compare prices" is likely to lose its sale price. Google has said to expect a fix next week and in the meantime suggests feeding sale price in place of full price. To make this easy in DotFeed, the rule will read
"If sale_price >= 0.01, then price ={original}"
Secondly, superglorious is wondering about a "range" on sales effective date. It's really easy to do this in DotFeed:
"If sale_price >= 0.01, then sale_effective_date = 2011-11-13T13:00:00Z/2011-12-31T11:59:59Z"
I hope that helps.
Jo Benson
COO
Vortx / AspDotNetStorefront