Novice Router Question

Whether the router is a bottleneck depends how fast your internet service is -- more so on how good your wireless link is. I would do the following before spending any money:

Experiment with different channels -- the different frequencies work better or worse depending on environs.

If you can detect neighbouring wifi, try to choose a channel at least 5 stops from the strongest (though see above).

Raise the router above furniture level.

Move the computer around so that the antenna is not masked by the computer user's body.

Having said all that, wireless B routers are getting quite old now and they don't last forever so an upgrade isn't a bad idea, but don't expect a miraculous speed up.