Apart from the colour, plus the shape of the "electronics box" on the top of the arm, it looks very similar to a (not very good) Einhell saw I purchased in Germany a few years back (my particular model now seems to be discontinued). The tools and table insert look very much like what came with my Einhell. IF memory serves, it cost me about 120 Euros new. I don't know the particular name brand of yours, but it looks pretty much like a whole range of similarly-priced saws available just about all over the place.
In short, from the picture it doesn't look to be particularly special/valuable in any way, but as you say, this one looks to be nearly new/little used
Assuming it's also in working condition I'd GUESS a price of roughly 40 to 50% of new price.
BTW, re the 2 pin plug. IF the electrical lead has only 2 conductors, not 3, then it's perfectly safe to run it with the 2 pin plug, or if fitting a UK type 3 pin plug before sale, then make sure that you do NOT connect the Earth (middle) pin!!! But OTOH, if the electrical lead has 3 conductors then you MUST connect the Earth (Green, or Yellow/Green conductor) to the Earth pin. Sorry if this bit is teaching granny to suck eggs!
HTH
