Please all sifus I need help.

I did some reading on diamond rings but still have some questions.

My budget is 30k to 50k MYR.

1. My girlfriend likes Tiffany and co, what kind of ring can I realistically get with my budget?

2. If give up on Tiffany and co, what is the next best branded diamond ring I can get from Malaysia?

3. Would it be cheaper to buy in Malaysia, Singapore or UK?