For macro, see
https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html
For ultrawide (UWA) and fisheye (FE) the options are mostly separated by price. The most flexible lenses are the great DA10-17 FE (the lens that drove me to Pentax) and one of the UWA beasts: Sigma 8-16 or 10-20's, Pentax 12-24, Tamron 10-24. I own and love the Tamron, which is also the least expensive of those. Still, none of those are exactly cheap.
For less flexibility (and cash outlay) the Zenitar 16/2.8 FE is just mildly fishy, and defishes nicely (where it's effectively 12mm), and is fast and pretty sharp, and can be had for under US$200 shipped. For situations where I want more speed and need less flexibility than my DA10-17 and Tamron 10-24 offer, the Zenitar works damn well.
Avoid UWA and FE 'adapters' if you care at all about image quality. Such cheap strap-ons are OK with video, and if you don't need images that look 'photographic', like posterizations, solarizations, etc. For reality-based photography, get the real thing.