Watch out for the pile-on fees many of the vbro's are starting to add, or increase. Can get as expensive or more so than a hotel. The one we have coming up is 127 per night, but some in that price range she looked at, the cleaning fees were as much as the rent. Read "details".
We have stayed twice at the Kona Seaside Hotel and would again. Not an vbro, but nice, locally owned, less expensive than the chains, and just very short walk to the pier where the Ironman starts. IIRC, the Hilton is just right across the street. (Might be another chain..). All kinds of restaurants and shops within a mile walk down the shore street. Beware - the walk back can get longer from some of those places...... shifty sidewalks.