I've been in wedding where I was expected to pay for the tux but never payed for the outing i.e. golf etc. The bridesmaids typically pay for their dresses which are more than the tuxes and then they are actually stuck with them.
As far as getting invited to be in the wedding party of someone you don't consider a good friend I would decline and say that you won't be able to do it because of work etc. and that you most likely will come in the day of the wedding or late the night before missing the rehearsal etc.
As far as getting invited to be in the wedding party of someone you don't consider a good friend I would decline and say that you won't be able to do it because of work etc. and that you most likely will come in the day of the wedding or late the night before missing the rehearsal etc.