Hi.
Jailbreaking should be easy as long as the jb is out.

The stores (any authorized reseller) sell the ipad as the same price as the apple store for the ipad and ipods. I feel that the ipods are cheaper in the US. You can check out www.apple.com.sg

Accessories wise, the apple store / istudio (one of the bigger reseller) does have quite a fair bit but its not cheap. I can remember one of the very good screen protector (the name is Power-something) cost like S$50 for the ipad. But its really good.

There are lots of little stores / booths on some streets selling very decent cases / skins for the ipad / iphone / ipods. I have gotten a speck case for my iphone for S$20. It cost like USD$30 in the US. If you have time, you can also check out the local ebay site. I was very impressed by the variety and the price. As Sg is a small country, many of the ebay sellers so have shops where you can pick up the items from. I once bought a very decent Speck case for iphone for S$5. Do check out Sim Lim Square (near Bugis MRT station). Its a computer hub. Cheap thumbdrives, computer parts, notebooks, accessories, camera stuff. Its all small shops, Prices there are quite transparent as many of these shops hand out flyers with prices. You can even google for it.

Have fun shopping and eating....