should you replacsomething that you break?

Definitely offer to replace it. Let them decide if they want to take you up on it or not, don't just go out and buy a replacement without asking. If the piece was one of a kind, offer to pay for it if you can afford it. However, and I cannot stress this enough, if you break something and you cannot afford to replace it, DO NOT OFFER. Apologize, and if asked to pay or replace, explain that you don't have the money, but you would be willing to work something out if necessary.

Remember, it is worse etiquette to promise something and not deliver than to break something, apologize for it, and move on.

Yes of course. Apologise and compensate.

Yes. Either replace with something identical or give them the money to replace it.

I would but I have morals some dont

If you break something of your own, that is up to you whether you wish to replace it or not.

If you break something that belongs to someone else, then, yes, you should replace it with the identical product or ask the owner how you can compensate them if the object is not available to be purchased any longer.

Yes. Or give them the money to buy what they want.

Yes. You should at least apologize offer to replace it.