Buying alcohol in Tokyo or Narita Airport?

The alcohol here in Tokyo is so CHEAP compared back to home.

I had passed through Malaysia before I got to Japan and the prices in Malaysia's duty free store seemed the same you would find in Canada. Canada's duty free stores are even worse. Alcohol is more expensive than if you bought it in Vancouver.

My question is: Will Narita's duty free stores be cheaper than if I bought alcohol in Tokyo? Or will they actually be cheaper than the stores in Tokyo?

I'm planning to get some red wine/sake/ and soju if the duty free store has it.

I cannot help you with your question. But I am curious; how cheap is cheap? Can you provide some example?

No - tax on on alcohol (especially spirits) is relatively low, so the tax free prices aren't much different in the airport when you take into account that the airport shops base prices are more expensive than in town. Cheaper to buy in Tokyo.

However, if you buy in advance you will have to pack in checked luggage - may not be as safe from breakage as if you buy inside the airport and keep in your hand luggage (although will cause problems if you have a connecting flight due to liquid ban). If you take in checked luggage make sure you wrap in waterproofing and surround with plenty of padding.

Don Quijote is has pretty good prices on spirits. But check your countries import allowances, could get expensive if you have to pay duty aon top for exceeding them.

Beer is expensive with relatively high taxes and a lot of the hops and malt have to be imported from UK/Germany/Czech republic which drives the price up.
Imported wine pricing seems fairly arbitrary with high import costs making up a lot of the price. Australian can be good value - but you'll see cheap low grade French and Italian wine at very high prices, while oddly you can also find good quality French wine far more reasonably in Europe and cheaper than the non-AOC stuff on the same menu. There are some good importers on rakuten and you could find a gem at less than ��2000 if it's not well known in Japan.
Spirits are the the real winner. Good foreign branded gin/vodka etc can be had for under ��1000 a bottle. Non-branded stuff will be even cheaper. However some brands will be twice the price that they are in their own countries - totally depends on the import batch and exchange rate when imported. Just shop around. Things that are famous and premium Japanese brands are often way overpriced.

Can be cheaper depending on what you buy. An example - Suntory Yamazaki 18 yr old whisky 150,000 yen duty free. Retail in Japan at least 165,000 yen. Suntory Hibiki 21 yr old whisky 150,000 yen duty free. Retail in Japan at least 180,000. Johnnie Walker Black Label 1 litre 3000 yen duty free but retail you can get 700 ml for about 2000 yen.