There is nothing dual band that I'm aware of, at least that's affordable. I hear there is some Kenwoods and Motorola (Astro Sabres?) ht's that can be found ~$300, and I've seen an older Thales Racal (sp?) P25 radio from the 90's selling for about $150 on ebay, but I hear the batteries are hard to source and can be as expensive as the hts themselves. All the ones I saw on ebay didnt come with batteries.
I don't know about P25, but there are some Chinese radios for DMR poised to do what Wouxun/Baofeng did for the amateur market and start releasing cheap DMR radios (well, cheap in the commercial market sense) starting about $200-300 or so. IF they can hit sub $200 and eventually sub $100 levels I can really see DMR/mototrbo take off in the amateur world.
Cheapest P25 Radio for Ham Bands?