If you have the "COM", the others are quite irrelevant, from a negotiation point. If you said to a buyer can we work on the price, if I attach these other extensions to the sale, in a lot of circumstances from the buyers point of view...nah. The buyer will say a good price for the "COM" please, not interested in you squeezing more out of me for the sake of the other extensions, or to help your side of the negotiation. However...this isn't "always" the case. Strengthening an online brand with further extensions is a good thing, but emphasising "COM" is what matters. IMO