i would like to know if it can be used with dslr camera
If your DSLR has a suitable mic socket then Yes. If not, then No. Kind of obvious, surely?
if i sell it how much its worth.thanks.
See Ebay - completed listings. Or search for specialist video enthusiast forums.
The going rate for used gear is generally 30% of retail so long as it's still current technology. You can get more if the gear is lightly used/unused and has some of the manufacturers warranty remaining.