Hmm. Yeah, international shipping on a subwoofer will get pretty expensive, as would shipping tower speakers. Best bet would be to look for bookshelf speakers with good bass extension I think.
Or if you're comfortable working with wood or know a local cabinet maker who could build speaker enclosures for you, you could get a well-respected DIY speaker kit. For example,
The Marksman Kit will have an F3 of 37Hz when completed.
The Anthologies, 32Hz. And if you build the speaker enclosure yourself or have a local cabinet maker build it for you, that'll be less that you have to ship internationally.
You might also consider building a DIY subwoofer locally. DIY projects can be fun, once you get over the initial fear, uncertainty and doubt.