Are you looking for a zoom ?
If you're ready to consider buying used, you may be able to find a Tamron 17-50mm 1:2.8 around $200-250. This would really be a step up from the 3 lenses you mention. Otherwise, there's the Pentax DA 16-45mm 1:4 that can also be found (used) around $150-200.
Originally posted by photoshoper Pentax 18-55mm sigma 18-50mm f/2.8-4.5 sigma 18-125mm non HSM version
The Pentax is honorable without anything brilliant about it, the Sigma 18-50 is probably a bit better but not by much, the Sigma 18-125 will be useful thanks to its range but is not a fast or high-quality lens.
If you are using a "WR" DSLR, the only WR lens in your price range (that I know of) is the Pentax 18-55mm.