As the other guy said - the -5 energy sux on an assassin because you usually need 20 energy to get any attack strings to function and you want 2 strings to spike damage then get out. Zealous (2 manage energy for a 2nd attack string) and defense would be my mods of choice (with a vampiric set of fortitude to switch to as backup just as an emergency in a tight spot) and the req ain't too bad because most Assassins will have at least 11 or 12 in dagger when looking to max their damage spikes on a hit and run.
If they had been 15% -10 when attacking or 15^50 they would have been worth a load more. I suspect you would get 5-10K (suspect they will be selilng for 10K in a month or two) if you salvage the zealous and 2K if you salvage the defence mod. Other than that you are looking for an eager buyer to offer you up to 10K right now (though that may be a tough sell).
Thanks for the explanation on mods ect i do not have an assasin cahr as yet so do not know the advantages and disadvantages of using one i will just sell them cheap
Um - just to let you know - zealous mods may be getting up in price faster than I thought - just saw someone selling one for 60K (which I think is ludicrous just yet) but a successful salvage may get you more than I thought if they are in short supply just now.