I wrote a short story using some infinitive phrases. Could you please check it?

Once my friend Andrew and I walked to my home just to have a drink together. On our way, I noticed a new block of apartments that had been built next to my home. “What a lovely building! I wish I had a flat here”, I said. “Well, to put it bluntly, I think it’s about time you bought a new flat. It’s a shame you keep living in your tiny studio flat that is actually a shabby lair, not to put too fine a point on it”, said Andrew. “But I don’t have enough money”, I answered. Then, to add insult to injury, Andrew said: “That’s no excuse. You’re just too lazy to do something about your living conditions, to put it mildly”. I had to admit that my mate was perfectly right.
To cut a long story short, the next day I chose a new flat to buy and before long I was the owner of this flat. That’s great to have sincere mates!

Question

I wrote a short story using some infinitive phrases. Could you please check it?

Once my friend Andrew and I walked to my home just to have a drink together. On our way, I noticed a new block of apartments that had been built next to my home. “What a lovely building! I wish I had a flat here”, I said. “Well, to put it bluntly, I think it’s about time you bought a new flat. It’s a shame you keep living in your tiny studio flat that is actually a shabby lair, not to put too fine a point on it”, said Andrew. “But I don’t have enough money”, I answered. Then, to add insult to injury, Andrew said: “That’s no excuse. You’re just too lazy to do something about your living conditions, to put it mildly”. I had to admit that my mate was perfectly right. 
To cut a long story short, the next day I chose a new flat to buy and before long I was the owner of this flat. That’s great to have sincere mates!

Answer

Yes, i would change "that's great to.." to "it's great to." Other than that it's very good.  But clearly you are learning British English, not American/Canadian English 😂

Answer

Very good! 
And you use some challenging expressions in the correct way.
The only change that I would make is the final sentence:
"That's great to have sincere mates!" 
"It's" is better than "That's" in this case.
And sincere mates sounds a little bit strange (but only a little), so I would write:
"It's great to have friends who tell you the truth."
Or something like that.
Молодец.
Удачи!

Answer

It's great to have true friends, even if you egg each on to drink too much. 
You didn't notice the new flats being built near your flat?

Victor, your story is written well. Only one or 2 points could be shortened, to make more concise.