What Patrick and the other guys have said. If the shoulders/collar aren't right, walk away. In theory, it can all be adjusted. In practice, it's very expensive and very few people can do it - far fewer than say they can. Chest, back, sleeves are easier, cheaper, and more reliably fixed.
The annoying thing is the same brand will often stock items made by different factories to different specs. Last summer, I picked up a bargain SC in a sale where the shoulders were great andd the rest needed doing. Bought, fixed. My cheapest SC and it looks very nice. Last winter: same shop, another nice SC in the sale on deep discount, but the block was entirely different and it was instantly obvious that the shoulders were wrong for me. So you cannot assume that just because one SC from Pineapple Junta did not fit on the shoulders that other SCs from Pineapple Junta won't fit perfectly.