The Crack is unassembled , the cost is for the parts, you have to assemble it yourself, so It will not be available used cheaper, as people will always add cost of labour for assembly.
If you are really tight on your budget do not buy the T90 without a demo (as they are very source, amp dependent), have you heard it ? Where I live almost 90% of the audiophile HP's are not available for demo, so when I buy HP's, I always factor in the fact that I might have a 20% loss on resale if I don't like them.
As you can see from the reactions on this thread the T90's are a 50:50 chance of hit or miss. If you are buying blind & cannot afford to resell & buy another, you can go for a "safer" headphone like HD 600.
So you can either go with the nice, homely, dependable girl or go with the ill tempered, finicky, Hot one.
. I always liked them hot.