My son is on Alimentum, for reflux, should he be switched now that he is better?

My son was first on Good Start formula, but was switched to Similac Alimentum formula at 2 weeks because he got very fussy, well here it was due to severe reflux. He was also put on the medicine Prevacid for the reflux. He is now 5 months and is still on the medicine but doesn't spit up very much if at all anymore. I was wondering what formula we could maybe think about switching him to. I am first gonna discuss this with his PED at his 6 month check. Any suggestions? Or will they keep him on this till he is a year? To me why switch a good thing, but WIC said they will probably switch him to something else. It is VERY expensive and i think that's why WIC said to ask his PED if he should be switched to something else. I dont think they like helping with it since its expensive. I buy the ready to feed anyways when the 8 powdered cans they give me run out. Has anyone elses baby been switched? And if so what formula were they put on after the Alimentum and did they do ok with it?