Since the straight razors are honed and stropped by hand, the edge and how it feels is a result of all of the following factors combined: steel type, grind, tempering, honing, stropping, shaving technique, and not just the brand of the razor blade as you are used to.
Razors 6/8 and wider, and/or stiffer grind will likely be heavier than the shavette.
Pricing depends on many factors - cosmetic condition and desirability of the brand being the top two. As far as brand new razors go, where you eliminate the condition factor you can check the popular vendors for reference - classicshaving, vintageblades, straightrazordesigns to name a few.