replace a laptop

I was told, here, that to replace my SB I'd have to pay $350. When I was in the MS Store I was told it would cost me $550. Is it possible the store price is due to a commission or was the quote I got here just way off?

I travel multiple times per year, at least once internationally, to provide training that includes PowerPoint presentations (avg = 15mb) and/or picture shows (avg = 300mb). I would like to travel with a tablet instead of my laptop. I want to be able to access the internet and my email, plus...