That's still the case if you want a high quality 2 carat diamond, but is it completely unaffordable if you are happy to settle for a lower quality gemstone?
Our price comparison on 2 carat diamond rings came up with prices ranging from around £1000 up to £25000. So whilst prices are clearly high, it is worth considering that the average person spends somewhere between £500 and £1700 on an engagement ring (depending on which study you believe).
The slight snag is that if you want to get a 2 carat diamond ring for £1000 then you will almost certainly need to buy second hand. That's obviously not for everyone, but bear in mind that diamonds depreciate hugely once they have been worn so you can get yourself and diminish any further depreciation if you ever needed to sell the ring (hopefully you wouldn't, but still...)
When I searched, I found a second hand 2.30 carat diamond ring on eBay which went for £1019. The grading was fairly low (I3 clarity, which is not great, but colour was G which is decent and a setting of 18 carat gold which is also good - see our beginners' guide for more on what this all means). On Etsy, the cheapest second hand ring I could find was nearly £1700. Obviously these deals change all the team and I could probably find a better deal with a bit more patience and perseverance.
If you want a new 2 carat diamond, the cheapest option was surprisingly not that far away from the cheapest second hand price, with an Amazon Marketplace seller offering a remarkable price of just over £1300. It probably does not need pointing out that it will be a low grade diamond for this price (I3 clarity, J-K colour, 18 carat gold) but it is not significantly different to the cheapest eBay deal.
The next four cheapest sellers in our study were all USA based jewellers (Overstock and SuperJeweler for example) who all offer 2 carat diamonds in varying qualities for under £5000, even after you've factored in import and excise fees (see the blog for more on importing jewellery from the USA).
If you'd rather purchase from a UK based jeweller then Diamond Heaven is worth a look (cheapest 2 carat ring was £5000), as it has a Birmingham store in case you need to return it.
High Street options are very limited if you want a 2 carat diamond, presumably because they sell so few that it isn't worth stocking such high value items. The only High Street jeweller I could find offering a 2 carat engagement ring was Beaverbrooks, which is perhaps not surprising as they are perhaps the poshest jewellery name in most towns. The downside is that their cheapest 2 carat ring will cost you £25000, although it was a higher grade than most in our study with a clarity of VS2 and a platinum setting which is generally more expensive than 18 carat gold.
I hope she says yes....