if your land is clean atm, id be more concerned with worming any incoming stock and quarantining them on arrival so worms arent dropped all over your parasite free land. worming weaners with noromectin or similar on arrival is, IMO, so important for preventing lice etc aswell as worms so it really is a no-brainer. its easier and cheaper to do a wee pig than battle with a bigger beast later on, and in the meantime they could be sharing beasties with all and sundry.
when you know you have clean beasts and clean land, then thats where worm counts are handy. id also worm on arrival even if the breeder has said they have been wormed as not all people are honest. its buyer beware.
to save money you have to source all your meds and worm counts online, and only use the vet when you actually need a qualified vet. dont pay a vet to do your shopping or it will be expensive - take control.