A company is trying to decide between two machine models to buy. The information of these machines, both of which do the same job, are as follows:

The purchase value of Model A is $55.000 and the service life of this machine is 4 years. It is foreseen that the sales value of the machine at the end of its useful life will be $14.000. The total annual operating and maintenance expenses of this model is $7500.

The purchase value of Model B is $85.000 and the service life of this machine is 5 years. It is predicted that the sales value of the machine at the end of its useful life will be $18,000. The total annual operating and maintenance expenses of this model is $5500.

For a long-term project (20 years), a solution will be reached by using these models (by purchasing them again when necessary). According to this; Which model would be more appropriate to choose and what is the NPW calculated for the total project duration of this model? (Current market interest rate will be taken as 12% per annum)