Discounts will be specific to your city, the bike shop in question & the make/model of bike. You can't simply say that every bike should/would give X% off the price of a bike. What you'll find though is at this time of the year there can be deals made if you find a bike you like in the size you want that is in stock. What typically happens is you tell them your budget, they figure out your size & they match you with whatever they have that's closest to your size that is in stock. You won't necessarily get the best bike for you, but rather they'll try & sell you the best bike they have to get rid of. I would choose the bike that I liked the best on the road and if necessary order it and get it when it arrives rather than taking whatever is in stock. You will save money by buying what's in stock but if it isn't a good fit you'll just be looking again next year.

I felt the same way about the Roubaix as you described & ended up going with the Madone.