You can usually find a stack of bait for 2-5k which is in my opinion, a decent price, PCNA. Otherwise if you wanted to farm them, any small critter (1hp animal), or insect/flying insect, will give you guts, crawlers, insect parts respectively, and farming worms requires you to pick plants for a chance at them.
I would look around a bunch of traders for enough of the bait you wanted or use the TTC website with advanced search and make the unit bar at 200 to find a good price on the larger stacks of bait if you wanted to go that route.
Grand Master crafter, all styles and all furnishing plans known pre U41.
Vamp and WW bites available for players.
Shoot me an in-game mail if you need anything, happy to help!
the most expensive one is probably the worms for lake fishing, as they are the hardest to farm generally
the other 3 are relatively easy (especially crawlers since they can drop from basically any undead enemy or 1hp critters)
also on PCNA, and i would say full stacks of everything but worms is around 1800-2000g each, worms tend to run a bit higher, usually closer to 3000-3500g each
i have my main house (grand topal hideaway) listed in the housing tours, it has multiple target dummies, scribing altar, and grandmaster stations (in progress being filled out), as well as almost every antiquity furnishing on display to preview them