Exactly what kind of analysis would you be using it for? It's quite good at basic linear analysis and will allow for gap formation. You can simulate bearing load distribution, input bolt preload, define friction coefficients and contact between faces. For us it meets most of our needs. This all comes with Solidworks premium which I feel is well worth the additional money. To perform more advanced non-linear analysis, frequency response, etc. you need to puchase Simulation professional or premium which costs even more than SolidWorks Premium. I don't have much experience with those.
By the way when did you purchase your SW seats? They are now running a promotion where you get a free upgrade from standard SolidWorks to SW Premium. Maybe you can ask for a deal.
NEI also offers FEA that interfaces directly with SolidWorks but I have no experience with it.
The only real answer is to get a demo and decide for yourself. Hopefully you have enough engineering knowledge amongst yourselves to determine is SW Simulation is adequate.
Don't allow canned demos. Have software demonstrated on problems that represent your needs.
I have opinions about SW Simulation's shortcomings, but those opinions are based on my own needs and experience.