I want to buy an extra stick for my laptop. Where would be the cheapest place to buy one? In North America, there are stores like NCIX and Newegg where you could get very good prices for various computer parts.

I think Panthip is for you. Now what shop in Panthip...

In Zeer, I'd say go to JIB, you're almost certain they have the best prices. You can check their price at jib.co.th, it will give you some data to compare with prices you are offered in other places. Now 10 or 20B difference may not be worth a trip to Rangsit.

Just Memory , 3rd Floor Fortune Town, near all the factory service centres , they will install and warrant.

You can buy second hand RAM if you are super stingy, plenty of junkshops in most IT malls.

In Thailand, If you don't have the IT knowledge to fit it yourself then I'd take it to your machine's manufacturers service centre, & have them fit it, it isn't the cheapest option but I wouldn't trust a back ally store in Pantip or Fortune Town to do it, especially if you have sensitive data on the Hard Drive.

I hope you won't mind me asking if Pantip is open for business and if it is safe to go there.

Thanks