Correct

换购

/ huàn gòu / 
Strokes

Example

As a Verb

part-exchange; trade in a used item for a new one

1
Huàn
换
gòu
购
yī
一
jià
架
xīn
新
xiàngjī
相机

part-exchange an old camera for a new one

2
Huàn
换
gòu
购
yī
一
kuǎn
款
xīnchē
新车

trade an old car in for a new model

3
Huàn
换
gòu
购
zhé
折
huàn
换
dǐjià
抵价

trade-in price/value