YMS

Is there really not a single answer saying “I would rather not make everybody’s lives more inconvenient just because I could”?

If there would be the kind of budget you’re talking about, they’d just buy a house, or rather three (one to live in, two to rent out, to re-finance the other one) and that whole question would be obsolete.

but is a given that the more expensive the wedding is, the shorter the marriage might be.

So have a dead cheap wedding and the marriage will last forever?

Blink has a younger code base that’s easier to build on. Gecko has been around since the early 90s and has some ancient evils lurking deep within.

They both are of very similar age actually. The old Netscape rendering engine originated in the early 90s, but Gecko was a rewrite from scratch that was first used in a browser in 1998.
Blink is based on KHTML which is based on khtmlw, which was written at some point in the mid-90s, but as well saw a complete rewrite in 1999.