three week old yeast starter still good?

So I am contemplating brewing today and have a three week old starter sitting in my fridge. It is the wyeast kolsch yeast.

I started it awhile back and brew day kept getting postponed. It fermented at room temp for two weeks and then I moved it to the fridge where it sat for another week. It has just had foil over it the while time........

I am wondering if I should use it and see what happens or just chalk up the six dollar loss and get new yeast and make a fresh starter......

However this means that no brewing would happen today.....

Tough call..... Thoughts?

Ideally I'd decant the starter and add some wort and let it go for a day. If it was a big enough starter you'd probably be ok to decant and pitch, although I'd expect a longer than normal lag time. If you had done a two day ferment and put it in the fridge you would have been better off. I've done long cold crashes of my starters with great results.