Dear Bro Mzkaung,
If you think you dun need this $750, by all means buy new lens or accessories to tackle your spending itchiness...
However, you should ask yourself whether it's worth to do that and whether this is a must...
For me, I have been buying lens and accessories ever since I went into DSLR, of course making lots of losses when selling them off later. I think it's a typical guy mentality to always explore new stuff and later realise not as good as expected...
As many brothers here mentioned, do only buy when you need them to help you make a better picture, if you are not sure what to buy, means you do not need them yet.
I have since stopped myself in these buying spree as I suddenly realised that I have forgotten the initial reason I bought the DSLR in the first place...that is to shoot my boy and family and capture all the beautiful moments together. The purpose of going into DSLR was to capture pictures more beautiful than normal PnS.
So, now I only have 1 camera body and 2 lens, 17-50 for outdoor and 30mm for indoor. Simple as that.
And it's really the subject in those pictures that will make you smile when you sometimes look back at these collections....not your camera or lens...and people who view your pictures dun even care what camera or lens was used...
So just ask yourself, what you want to shoot and what is the purpose you bought the camera for, then you should be able to control your buying spree...
Market not very good nowadays, of course if you are damn rich or have rich daddy, then forget all what I have mentioned, but if you are like me, a normal peasant, keeping more cash in pocket would be the wiser choice.
P.S: I will truly repect those who make really nice pictures out of their simple gear such as kit lens, but if I see pictures from those who took it with expensive gears, my mind will only tell me, "ok, he has good gears, so expected..." So it's kinda like being first in a lousy school sounds better than being last in a top school...