Expected lifespan of a Linksys wireless router

I have a wireless home network with four different computers with varying Windows operating systems all accessing our satellite internet service. My company computer remotely connects to headquarters via a VPN connection. I seem to go through a wireless router about every year and half to two years. I know it is starting to fail when I begin to see a drastic slow down in performance, followed by intermittent service, followed by complete failure. I have three questions about my situation. First, is this the typical lifespan for this hardware in an above-average user home environment? Second, what exactly fails physically on these systems (I've had three different models of Linksys wireless routers -currently the SRX200 model). And finally, is the typical hardware failure an easy repair by the manufacturer (i.e. should I attempt to buy a refurbished router to save money)? Thank you kindly to anyone with advice.