Rule of Thumb - Take your build cost and then subtract 10% .... then 5% for each month of age for 6 months (60% value at this point) ... then 10% for every 6 months thereafter.
0.5 year old - 60% of build cost
1.0 - 50%
1.5 - 40%
2.0 - 30%
2.5 - 20%
3.0 - 10%
So one year old....about 50% of what ya paid for it