PCs:
1. branded PCs tend to have low quality components (mobo, psu, etc.) and they are overpriced. (Lenovo, HP, Dell, etc.)
2. custom builds from well-known builders are usually in better quality but extremely overpriced.
3. choose your component on your own and ask a store to put the together is better. you have the control over quality and this should cost slightly less.
4. choose and build your own PC. the cheapest of them all and you have the control of the quality...plus..if you haven't done it before, you will be smarter after you built it.
If you are going for nr. 1, I would not recommend that.