meatpants

hey- i have a 2008 Manitour R7 MRD TPC 100mm fork. recently i went riding, and during my ride i noticed that it did not have as much travel as usual. as my ride progressed, it seemed to get worse and worse. i took it easier than normal, as something seemed weird, and towards the end of my ride, i heard a loud crack from my fork, and it is completely locked up.
i've blown out forks before, but usually, it ends up being the opposite, where it is super spongy, and won't lock out for nuthin'.
as it sits now, it is completely locked out, as if i have it dialed into lock out. i released all of the air out of it, but this did nothing.

i'm just wondering people's thoughts as to where i should go with it, before i just go down to my LBS, and have them tell me it's $150 to fix.

i really like this fork, as it is pretty much one of a kind- in the setup i have it in.

thanks in advance.