Old folding bikes (even very old) can be excellent opportunities because many folding bike owners don't often use their bike and for very small distances. Its for instance the case of boat and small airplane owners.

So, its possible to find very old folding bike in a like new state.

Since its a Birdy 1, it has rim brakes, look if the rims and brake pads are the original ones and at the wear of the rims and brake pads to estimate how many km the bike did.