Sellers really try to ship immediately. Things occasionally hang this up. On the outside world, if you live in a country outside the US, look at your customs first. We cannot help how long it takes to clear unless charging a substantially higher rate.
Communicate with your seller. Ask why you have not received your item? Paypal glitched, and we did not receive notifications for two days. Should we be held responsible. I guess so, but ask. It helped us discover the problem and fix it. We run on processes, and if the processes are messed up, and we don't know they are, there can be a problem.
Don't resort to feedback until you have emailed your seller about a problem. New eBay users do this all the time, and it angers the seller. If they don't respond positively, zing 'em. If they do, give them the benefit of the doubt. File a Paypal chargeback as a last resort.
I hope you find many deals on eBay, and take this advice to heart.