I'm a twenty-something in a city with a high cost of living. I move every time the rent goes up. So i usually buy a mattress that will last me 1-2 years and then when i move it goes to the curb/craigslist. This means that my price range for mattress shopping is around $150. The last one i had was an Ikea Sultan mattress. It became increasingly uncomfortable in a matter of months. This new mattress- the Sleep Master- was about $40 more, but with free shipping it ends up being the same price as the ikea sultan + shipping. The Sleep Master 6" is absolutely amazing for the price. It's only been a month, but my quality of sleep has actually increased. As a side sleeper, i feel supported much more than with spring mattresses or the old ikea mattress. I've yet to see how age will affect it, but if anything changes, i'll be sure to update my review.
--update 11/18/13-- Eight months since purchase and i stand by my review. This mattress is still very comfortable, hasn't lost its shape or firmness in any noticeable way. I have machine-washed both the interior and exterior covers a few times and they have not shrunk. I'm very happy with this purchase! It's an incredible quality for the price.