Spending $150 in the hope of selling it straight away for a profit might not be easily realised, bear in mind if you sold on ebay then you'd have to resell it for $170 just to break even. Pocket watches, even Longines, are not as much in demand as Longines wristwatches.... but condition is all important, and that one does look nice (but impossible to say anything for certain from the pics). You also have to be assured that it is working perfectly, if not then (here where I am and from a very friendly, inexpensive, old style watch repairer), it would be another $40 + for a service. If you can guarantee it has recently been serviced then people will pay a little more $ for peace of mind.
I presume the case is silver, and if I bought it I'd be interested in inspecting the decoration. I would then decide on a good price and stick to it. It isn't something that you'd want to start at 0.99c
If you are still thinking of buying it, ask them for a photo of the inside of the case. also a better one of the outer case