USPS Can take anywhere's from 5-30 Working days for regular old Postal shipment, If Priority mailed things would be diff.
I've never had it take 30 days to recieve nor send a package but if you ask the Post teller next time when your at the post office you'll quickly find that what I'm writing is true.
As for not replying right away, I have done the samething numerous times, I'm not saying this is the case but I've had a numerous amount of people buy items from me and take 1-2 weeks before sending payment, On the day of recieveing payment or within 1-2 days it never fails to recieve a e-mail "Have my parts been shipped", Parts are sent but e-mail is deleted.
Funny as all hell a buyer thinks he can take his sweet-Ol" time about paying but once payment is sent wants items next day :roll: