Those are the only weapon prices that actually make sense at the moment. Bows especially are by far the easiest weapon to use and put out the most damage with. They should be the highest priced for the best versions considering lower tier bows still do almost the same damage and you only need the best bows when facing heavily armoured opponents.
Good bows should cost the most followed by good armour followed by good horses and then good civilian clothing/weapons (throwing knives for civilians please otherwise they do nothing). The good shields followed by good throwing weapons. Melee weapons should cost the least as the differences between tiers matters very little and fighting on foot in melee is by far the most difficult way to play the game.
Considering you can get 50K without really trying just by fighting Looters and a handful of quests in less than 2 hours realtime of play 50K for one of the best weapons in the game is cheap, in my opinion, a fair price for that bow would be more like 120,000.
Crossbows... well at the moment they simply do not do enough damage more than bows to compensate for their much slower reload speed and animation interruption (you can shoot a bow while moving, moving at all completely resets crossbow reload). Until crossbow damage is at least +20% or more compared to same tier bow then crossbow at any price is a waste of money.
