Replacement gaskets are cheap and easy to find these days... if you can find a brand name somewhere on it, really easy, otherwise just go with the most common brand (Bialetta, I think). Here's one site that offers replacements with precise measurements for matching (http://www.fantes.com/espresso-stovetop.html#gasket); there are many others.

I'm aware that I'll need to replace the gasket eventually, but I'm okay with that. As maintenance goes, it's not bad.