The truth is it's impossible to be certain of anything just from those pictures on Ebay .... but if you like the look of it, it has a very low starting bid, then go for it, but as mart says you must always consider the possibility that it isn't necessarily as described.
There is wear to this lamp, and a degree of patina, all of which could be faked I suppose, but the lid 'hinge' is interesting. I don't think it was made yesterday or last week .... but could it be 100 years old? 200 years old? Who knows ...
However, take a look at what this seller has sold in the past, s/he seems to have sold a few interesting although not necessarily expensive pieces. Back in June they sold a Persian Islamic tray for $331
Large Fine Islamic Persian Qajar Brass Tray Qalamzani Work Birds & Foliage 15"
The buyer of the tray seems to have an interest in Islamic pieces so was obviously fairly convinced that the tray was original. If this is an interesting piece, then I think you'll see the bids start to mount .... if it stays cheap, then maybe snap up a bargain?