2100 MSP costs about $26/£17 and half of that is $13/£8.50 and half of that is $6.50/£4.25.
So I'd say around $5, not a lot to be fair.
I remember people that sold 100 MSP codes for about $0.75-$1.00 each but then again that is 100 MSP codes so they usually sold bulk for $0.50 each.
I'm gonna say the 400 MSP codes would be around $3.00-$4.00 each.

