That is a different pump then i have seen.Here are some pictures of the pump, installed, including the model number. I'll pull the pump later today and try to get some pictures of the bent flange as well as the area that I think the leak is coming from...
I have pointed out two of the four 7/16" bolts that I remove to unmount the pump.
Maybe thats why it's so expensive.
Look around you should find better prices than that.Used maybe? I bought 3 used Grundfose this summer for $20 each.When he delivered them i got 4 because he found another under a pile of stuffs