8k can't get much.

A good sofa cost at least 6k onward.

If she's willing to settle for a cheap ring, just get one only.

But in my honest opinion, it's one in a lifetime thing, so go crazy a bit is okay

Just cut back on things like wedding receptions and etc.

Define reasonable?

Color F should be okay.

VVS1 also not too shabby.

If it's certified by GIA, should be no problem much.

I am not a diamond expert, so for me, what's acceptable maybe not acceptable for others.

Most importantly, your GF like the ring or not?

If yes, go ahead and don't think too much about it.

You maybe can get better deals out there but if she don't like it, no point as well :/

Or you could buy 1 Tiffany and tell her, look, this one cost a bomb.

So no need another 2 rings la.

Daily use unlikely to wear diamond unless she works at some uber high end place.

In fact, I don't see anyone in my office wearing a diamond ring to work ( except for one but that's because she's engaged. Once married will probably switched to a wedding band )

So, try my suggestion instead.

She'll probably like something from tiffany, then you can tell her you buy for her one expensive one can already.

No need so many coz won't use

But if you fail, prepare to lose more than 7k 

She already like 0.31 carat diamond.

You think she will settle for a plain gold ring for that price?

Once you open the flood gate, high chance you won't escape paying that much

Sidenote : Don't think about resell value.

Once buy liao, impossible to sell unless divorce

For me, that's how i consider my purchase lol

Gold bar = yes.

Gold ring = no.

There's a difference between the price for gold and gold ring.