I posted my review of the T-Mobile Dash 3G back on 30 June. The Dash 3G can now be purchased from T-Mobile and as you can see on the T-Mobile site the full price is $349.99 and there is a $180 instant discount for new lines of service. A reader, Nicole, sent me a note that there is a Costco coupon that runs from Monday, 13 July to 2 August, where new customers can save even more and even existing customers may get a great deal.
According to the Costco coupon (I took a picture of the one I have at home) there is a $210 instant savings for new 2-year activations or customers with eligible upgrades. That would bring your Dash 3G price down to $139.99. Then there is another $50 mail-in rebate for those that sign up for the $24.99/month unlimited data plan. This means that new customers can pick up the T-Mobile Dash 3G for only $89.99 from Costco, compared to $169.99 from T-Mobile. Existing customers, with eligible upgrades (not sure exactly what this means), can pick up the Dash 3G for a decent price of $139.99.
If you are an existing customer then I recommend you try to find a Costco with the Dash 3G since that looks like the only place you may qualify for any type of discounted price from the $349.99 suggested retail price of the Dash 3G. If I didn't just move my whole family to AT&T I would be at Costco on Monday when this sale kicks off.