Amazon is offering prime members an Echo Dot 3rd Generation + 1 Month of Amazon Music Unlimited for just $8.98! Note that this is only available for new Amazon Music Unlimited subscribers only. Also, the subscription will auto-renew, so you'll need to cancel your subscription once your Eco Dot ships if you're not interested in keeping the Amazon subscription service.
Non-Prime members can still get this deal, but it's $10.98 + $5.99 shipping.