Remodeling a bathroom, a little help here?

So it has tiles from the 60's and they are UGLY!! if you buy shower liners can that just install right over the tiled walls? Is it really expensive?

Not cheap that's for sure, but they are 1000 times quicker and actually look like a brand new tub/shower. I'd say shop around and get prices, then price getting someone to remove and replace the tiles. Might surprise you which is cheaper.
If you want to just put the shower liner right over the tiled wall that would probey be ok , but because it is a wet location you might wanna use a moisture resistant drywall (greenboard) behind the shower liner just to make sure that you wont have a mold problem Greenboard cost a little more then Regular drywall but will pay off in the long run