After giving maasor and spending only what one really has, not borrowing from credit cards or gemachin (one is not allowed to borrow what they know they cannot repay) then if they have the money and there are not part of a community which took upon itself tekonos regarding spending, there’s no reason that they cannot spend “excessively” for a simchah.
However brocha is only in what is hidden and tznius. Excessively lavish simchos are not tznius.
And we only take with us after 120 years the schusim of our mitzvos so it’s rather foolish to spend money on chachtkes or to gefel others.