Sounds good to me. I've got the same Surface Pro3 configuration, does everything I've wanted it to, but I've only got one pen - the original it came with. I'm sure I paid more than $800 - nice find!
Got the same deal (minus the pens) on amazon used market place. Paid about 700 for the surface, 50 for the keyboard and 50 for a charger for the 256 8gb i5.
I think it's a great combination of portability, price, and power.