Gift ideas for a wedding?

[DeliciouslyDecadent]

I want to buy something for a couple we are acquainted with but not close friends. They are in their early 40s, been living together for ages and are getting married. (Bought a house together years ago.)
They are well-off and want for nothing material (no kids.)

My budget is about £20.

I did think of champagne but the price is too much.

I wondered about a nice candle (boxed) ? But I'm really stuck.

I don't want to give a voucher as they are both in very well paid careers and it would a bit meaningless.

A house plant in a nice pot.

A bottle of nice port. £20 will get you an interesting and decent bottle and it's a bit more unusual than champagne.

I'd buy them a bottle of Cremant de Loire. It's as lovely as champagne without the price tag.

If they have a garden, maybe a rose tree.

I'd go for something for their garden too. A rose bush or a shrub or a wind chime or a bird box or a pot for their patio etc.

Even in a well paid career I'd probably rather have a £20 voucher or cash than loads of stuff we don't actually want.

Port is a good idea they can crack it open at christmas

Not a wind chime!!!!!

Maybe a bug hotel

They've just had a prof garden makeover so no room or inclination for pots etc.

Booze ideas good as they like that!