Are you talking about just the ads here on RCU or anywhere?

Tower has recently announced that it's going to do some overseas shipping to select countries.

Having shipped an item or two overseas I can tell you that I think the reason most folks won't do it is because it's such a pain...

First, it's expensive. Most folks don't want to pay what it costs.
Second, it's time consuming filling out all the paperwork and packaging for that kind of a trip.
Third, things can get held up in Customs then there's always a fight about who's going to pay the duty even though convention dictates it's whoever is importing the item.
Fourth, unless you go with really expensive shipping options you can't get insurance on things shipped overseas so if it disappears enroute, who's responsibility is it?

I dare say a lot of sellers would ship overseas if you are prepared to pay them for the extra expenses and hassle. Some have just had bad experiences due to one or more of the considerations I mentioned above, and just won't do it anymore.

JMHO...