mage and wiz and drui and shm can get buy pretty darn good on store bought spells
necro and enchanter do fine until their 40's on store bought and don't need the big ones until they attempt hardmode stuff
bards are insane butt u cant solo indoor summoning mobs rly and i think they get all their spells from a vendor too
and SK is easy to solo and pretty dope down the line dope enough to do some decent stuff solo to twink alts
i highly recommend u have a porter and drop transfer all the words and runes that are reelevent to them and store up a bank full (thats what i got goin on my lilmule)
https://wiki.project1999.com/Skill_R..._Worth_Keeping
here's a short list i editedd it into a notepad )) for ease of use for myself
sell all the rest or let them rot
it takes about 2k to max out research on a lvl 50 or so character or get it close to 200