If you import two years old, it will benefit you. Remember you would have to pay atleast 50% duty whether you import two years old or 5 years old.
With prado, other issues are shape, more than two years old would have old shape, so it is not going to attract buyers.
Best thing is to import from japan, because japanese models (TZ) have full options as compared to UK models. Make sure it is automatic otherwise you will struggle to sell your big car.
Duty is calculated on the price from manufacturing country. For example prado's price would be determined on FOB japan, it would be standard price excluding any options. If price of brand new prado in Japan (FOB) is Rs 18 lakh, and other accessories are worth of 2 lakh, total price would be 20 lakh. So duty would be calculated as following.
Rs 2000000* 75%= Rs 15 lakh
and if car is two years old, depreciation would be allowed as 2% for each month.
two years (24 months *2%=48%)
Customs duty=150000-720000= Rs 780000
so customs duty is Rs 780000
now sales tax is 15%
CVT is 6%
Income tax is 2%
total= 23%
Rs 780000 *23%= (sorry no calculator) is what you have to pay.
These figures does not include port charges, any container charges or damarages or clearing agent fee. You should expect one lakh for these expenses.
I hope it will help you.