@askingaquestionaboutthis I'm getting the feeling that you feel a bit attacked or ridiculed here and that's a shame when you're obviously very excited by your DP thinking about proposing.
First off, it's ridiculous for PP to say that MN wholeheartedly condemns lovely weddings and thinks no one should ever spring for more than some sad sausage rolls and warm Liebfraumilch. On the other hand, dangling a carrot but needing years to save up for the things that ultimately aren't the most important things, is a concern, not least because of what it prioritises.
I would urge you to educate yourself about why people form partnerships, what a legally certified partnership means and what it offers and what you miss out on if you don't have one. These things are very, very important if you need to call upon them
/www.citizensadvice.org.uk/family/living-together-marriage-and-civil-partnership/living-together-and-civil-partnership-legal-differences/
There is also a link on that page to follow and read up about marriage. It's imperative to check this out if you have children, money or property together and for scenarios such as the rights of a next of kin.
You should also look at your Wills and Power of Attorney. These things aren't exciting like wedding planning, but they are things that protect you in, heaven forbid, the worst case scenarios of life. You won't find many people advocating to spend time or money on them, but you'll certainly hear a lot for people in distress when they hadn't planned and needed to have done.
You are a partnership and I do appreciate that you don't want to dampen your partner's ideas of doing something lovely for you, but by the same token, he should listen to you and what you want.
Obviously I'm not you, but if I were in your shoes I'd crack on with at least a civil partnership, a simple wedding ring, nice dress and a good meal afterwards and then plan and save for the sparkly ring and fancy do when you've saved the funds to finance it. If you did that, you could host a humanist ceremony and a reception party in any kind of venue you like, it wouldn't need a licence, the promises you make could take any form as you'd already have protected each other with the legalities and you could focus on the splashy celebration elements. I mean if you wanted a civil partnership ceremony you don't even have to tell people or wear a ring, it could be kept private, so your later 'wedding' would be everyone's main focus.
Just food for thought.