The factors involved change, that the 10179...it's no longer avaliable and eBay is more like private buying/selling (yeah, I know businesses use it too) rules governing eBay a little different....good old supply and demand, short supply + high demand = $$$$$$.
Where as retailers or service providers it's all to do with competition in the market place, note the pricing on say the forest police station way under the rrp at BigW but on the beam at say Toyworld, but not over it. Then there is the funhouse, over priced and available at only one chain store, no chance for the price to become lower through competition. I know for a fact I can also get the funhouse else where imported in, but it's the same price mostly likely through shipping costs etc.,.
I agree with TRU's customer service, I feel it has dropped in the last 12 months. Personally I avoid going into a TRU, unless I have to.