Nobody ever thinks of keeping the cardboard box, that's why they're so collectible! :)
Yes I have the Mk1 and it is in mint condition, but can't say the same about the cardboard box, I mean in the 90's the last thing I was thinking was keeping my cardboard box, that was in the storage room, to be in mint condition hahah. But I took good care of the cartridges and the console. I will have a look into it anyway. Cheers.
Its made by AT games, you know well enough to steer clear of that
Unless it's in very good condition, fully boxed, then you're looking at between £10 and £20 for it. Very good condition, with a decent condition box, and all cardboard inserts etc. will probably fetch between £50-75. If you have a Mk 1 console (identifiable by an extra port on the rear and the words 'high definition graphics' around the cartridge slot) you might get a little more for an unboxed console. They are more desirable because they have a higher quality sound chip on-board.
Dodgy emulation, yes, but leaps and bounds better than that SEGA Classics Collection doing the rounds on XB1/PS4 at the moment. If you were going to buy one or the other, you're better off getting one of these. You can get them cheaper if you shop around the second-hand market.