This is sort of off-topic but pertains to second-hand retro gaming in general, specifically buying or selling on the internet.
I moved recently, and before I did, I offloaded a lot of items in my collection on eBay for the first time in several years. (Some of you might have picked up a few items in the BST thread here as well.) I live in the US, and one thing that I noticed on this round of selling is that I got a lot more interest from international buyers than I used to in the past. For example, a lot of either common or generally undesirable Genesis games that I wasn't able to sell individually on GAF ended up selling on eBay for an average of $5 per game, in auction format, despite having a very low starting bid ($1 per game), not including shipping. Literally every bid on this particular auction was from either Brazil or Russia, from about 4 or 5 individual users. I was pretty pleased with the sale price since I was just cleaning house and didn't expect to get much from this particular lot. Some other listings went a similar way, and I attributed most of this to either a more knowledgeable modern PAL audience seeking 60hz games or maybe even a weaker dollar or something, but I've discovered recently that it's probably eBay's GSP that put a lot more international eyes on my listings, specifically because I don't use it.
When I started listing my items in the summer, I kept getting nag screens to enroll in eBay's relatively new Global Shipping Program, which wasn't around the last time I sold anything on the website. The sales pitch to US sellers is pretty simple: Instead of having to fill out customs information for international purchases and risk shipments being lost in a particularly unreliable overseas postal system, all you have to do is mail your shipment to eBay's US distribution center, and they'll cover it from there, offering international tracking on all packages and shielding you from any further liability as long as you can deliver the item to eBay, since any mishaps from that point on would be completely out of your hands. Not a bad sales pitch, but I declined for what was (to me, anyway) an obvious reason: it inserts another middle-man into the transaction that would likely take a significant chunk of my potential earnings. eBay doesn't disclose the costs of the program to US sellers at all (what specific fees there are, how much those fees are, and who pays for them), but from personal experience with courier services that I've had to go through to buy some stuff from Japan, I expected that they'd be fairly significant. So, I opted out of the program and never really gave it a second thought. Filling out a customs form myself is hardly difficult or time-consuming.
It turns out, though, that a lot of US sellers that sell internationally, definitely most of them, are enrolled in the GSP now. And I've heard that not only are the courier fees significant, but they tend to always impose import duty fees on top of everything, even on shipments that would be well below the tax thresholds for international commerce set by most countries. I've also read stories about the GSP distribution center opening packages and removing some of the packing material to lighten the load and skimp on shipping costs.
With all of that in mind, it's not surprising that my auctions that offer basic First Class International shipping (the lowest rate offered by USPS for most shipments) draw a lot of international eyes compared to similar item listings on eBay.
Something to keep in mind if you're in the market at all. If I lived overseas I'd definitely ask certain sellers if they would be willing to circumvent the GSP. I doubt most of them even consider it since the extra costs are hidden from them altogether.