What's the lowest selling system you own, was it worth it, and why/why not?

[Kaunisto]

Not having had much, it'll be Master System. And hell yeah, I'm still playing it at least once a year - tradition to dig it out for christmas. Though it's just barely running: image blurs, one pad left barely taking all buttons (and D-pad is broken), takes few starts to get it to read cart and light gun won't take from side of screen...
But with 36 years coming up and with some rough treatment at that, certainly worth it. It'll be a terrible day when it no longer turns on.