I have a cello that i am wanting to sell that does not have a "brand name" how much will it sell for?

i bought a cello that is custom made, i am the second owner, it is a full size, and it has no name brand on it except one name on the bridge, when i bought it i paid 800 for it, and was told it was a custom made import...do you think if i sold it i could get at least half of what i paid for it? i mean, how would i even know what it was worth?