Miu Miu's suede studded platforms retail for $490 at Barneys.
I first saw these Steve Madden platforms on the fantastic blog Cupcakes and Cashmere and they just appeared on the Steve Madden site! They retail for $149.95 and you can click here to purchase. Please note they're not expected to ship until 5/28/10.
*Update - 8/2/10* - If the Steve Madden version is still more than you were wanting to spend, Go Jane has a similar option with a thinner heel and minus the studs (available only in the tan color shown) that retails for $30.90. Click here if you're interested in purchasing.