It depends on the aircraft. Look at the used mkt and if you see many planes like yours for sale in used mkt, then that means people are not buying them. So yours will sit in the mkt for a long time next to those.
But if you buy an a330, then I'm not alone when I promise you that for now I will snatch from you at a nice premium. As a rule of thumb, look at the global statistics for planes and if there are a lot in use AND on order, then that plane is common to other's fleet so it will be more liquid.