Madrat the Rescue I got most of my pigs from is now neutering the boars if they are old enough, so they're ready to go with females.
IIRC they;ll be charging £40 for them (my GP3 cost £58 to neuter at our vet but the Rescues have a special rate with their vets, the volume of pigs would be more cost effective too)
Pigs (being the vastly superior members of the small furry variety
) don't need vaccines .
Fernie oddly enough, I get told the same by my pigs though I tell GP5 (Oreo) that they should've paid ME to take her away 
Every rescued piggie frees up a space for the next piggie in desperate need , some of them aren't just unwanted but neglected (hence the constant need for funding to nurse them)