I'm a very casual/beginner level ham and as such have mostly avoided committing too much in the way of financial resources - I have a UV-5R for a personal radio, anything else I do I've used others' radios.

I don't mind the 5R's interface; I'm familiar enough with it now that it doesn't really bother me. That said, it'd be nice to give it a little boost without spending a bunch of money and/or buying a new radio. I typically operate at home, so mobility isn't required (though being able to pack it up to have along when traveling wouldn't hurt, either).

What kinds of low-cost options are there that could help improve its range (and/or SNR)?