Are you talking about the ones where you move the ball with your finger? I saw one in a store very recently.

At the other end of the spectrum, after my last Logitech keyboard started to go after years of abuse, I picked up a "comparable" MS replacement since the model had been discontinued in the time since I'd bought it.

The MS board lasted about six months before keys started to fail.

I promptly ordered a new Logitech online, and it's now got two years so far on it.

 Yeah, I never liked their keyboards. For some reason, every MS mouse I've had has been nearly bulletproof. 

Both Logiteck and MS make differing levels/qualities of product....and in all cases you get what you pay for.

Cheap is typically junk.

My Logitech keyboard is a fair few years old now...runs as good as it ever did....but it cost the 'wrong' side of $300 [if I remember right]...

One of these....

The mouse is quite a bit older....still perfectly fine....from MS

You get what you pay for....

Always wondered why, when folks find a mouse or keyboard they really love, they don't go and buy a second one?

We backup our systems... so why not the peripherals?

I have a spare mouse.....

 Heh, your mouse is a slightly newer version than what I have now. Also, my keyboard I don't even know how old it is. It's an IBM, heh. I paid very little for it a very, very long time ago. I've had dozens and dozens of keyboards. I don't even know where they come from to be honest. They seem to multiply somehow. I think I've bought MAYBE two keyboards in my life (been using computers for almost 30 years). I never seem to break them, but I also have about 5 or 6 keyboards laying around in case of failure.

I am really thinking about this one :

Had the wired trackball for years in my old company:

This series of Trackballs is the best one can get. Feels really natural to use.

I have that and absolutely love it. Highly recommend.

Carl, I have the Logitech m570, and I really love it.

I thought about a SideWinder, but one costs about ten times as much as the original one I had, and I also have the tendency to accidentally drop my mouse often. The SideWinder doesn't look like it could still work after being cracked open several times. That's why I think it's a conspiracy, they've intentionally removed all cheaper mice with vertically stacked side buttons. It's driving me insane, more so, I'm driving other people insane. I actually got a store clerk from the place I bought the original one to dive into a pile of mouses to find another one. She was never heard from again.  

I think I will get one, It's 55 Euros at Amazon.de at the  moment. Although my M705 is great also. I love the unified receiver concept. Have a K340 connected on top.

On accident I literally paid for two sets of my logitech mouse keyboard combo. Loved them since never failed me. MX5500

i had 2 trackballs by logitec, both were pretty expensive, both of my track balls stopped working, so i stopped buying them, which is a pity

cause i truly loved them.

i actually have a microsoft mouse now, purchased about 2 years ago, still working fine...

I have spare Mice and KBs - but all are the cheap kind.  Still, they have not failed me yet (the only ones that did were wireless MS KB and mouse and I never liked the suckers anyway)