I'm not a sales person, but if I were to do it, my strategy would be to do a survey on the surrounding market and see what others are offering. ALWAYS KEEP IN MIND THE THEORY OF SUPPLY AND DEMAND.
First, put yourself in the shoes of a tenants or purchaser on what will you be looking for.
From there, we could have an insight of what your potential tenant or purchaser will be looking for.
I.e. you are offering an unfurnished unit, but in the market, a lot of others are offering partly furnished unit at a lower price. Hence, through this you should know where's your stand. If you do not plan to furnish it, you can also expect a very low rental/selling price for the unit.
If you are going to do furnishing, then make sure you are only furnishing the necessaries/basic starter pack, at a very standard cost. The brands of the products might not have any impact to the rental/selling price of the unit. (I.e. items that are necessaries to a tenant daily usage but irrelevant to buy for rental.)
Lastly, put yourself into the owners shoes when choosing potential tenants/purchasers.