The comic shops that around me have wall books but every time I find something good they jack up the price and they say they can't budge on it any tips?
Yes. Don't go there anymore.
If they are jacking it up when you are asking about a book or when taking it to the counter and the price goes higher than what the sticker says, that is a move. HOWEVER, if they know you are a "flipper" they might be treating you a bit differently. Have you ever "irked" them before?
Example - There is a known shady flipper guy in my home town and he is a individual_without_enough_empathy - He asked the owner for a bunch of books. Said he was trying to build a run (this is when he was still "new" to the area) then when the owner brought him all those books (out of storage), he only "picked" a few, the "keys" and said he changed his mind and didn't want the rest. There was a significant amount of books from what I was told too.
...After that, my LCS no longer lists variants for cover price and he started basically marking previously below FMV items up to FMV. Thankfully, I am on good terms and I am a long time customer but this one guy ruined it for a lot of others.