A 20% discount is 20% off the current price, and a 10% discount is 10% off the current price, which is 10% different from 250 yuan. It can be concluded that the purchase price of 10% is 250 yuan, and the purchase price is 2500 yuan.

Set the purchase price to x yuan.

Formula: 90% x-80% x =100+150.

10%x=250

X = 250 divided by 10%

X = 250 divided by 0. 1.

x=2500

(Resolution: "90% x" means 90% of the current price, "80% x" means 80% of the current price, "100+ 150" means the price difference, and "90% x-80% x" means the price difference 10%).