Saleability is the noun: how easy something is to sell, or whether it can be sold at all. A phone with a cracked screen has poor saleability. A flat in a good school district has high saleability — buyers want it. People in business, shops, and housing use it when they talk about the thing as a product, not about a special offer. It is a bit of a paper-and-meeting word; in speech many people just say “it will sell” or “nobody will buy that.” You will also see the spelling salability, especially in American English. Same word, fewer letters. Saleability does not mean “on sale” (cheaper this week). It is about whether the thing can find a buyer, and how readily.