In possibly the best move since it’s introduction, Marketplace has today seen an update.
This one enables picking the install location (storage card, main memory) which puts it ahead of Android which lacks that without third party software (such as Apps2SD) and also enables a picker for choosing with countries marketplace you want to use. This puts prices in the local currency, and from my limited testing works well!
You may need to uninstall and reinstall Marketplace to see the update though I guess it will be pushed out shortly.