I recently booked a trip for our honeymoon to Bora Bora through Costco (they were great). The only thing is, they do not setup the domestic flight to LA from Chicago. They do not get any great deals so go ahead and book on a flight with good fares to LA and then everything is taken care of from there.
I booked on one of the airfare web sites. I had not flown Spirit, so I had no idea how bad they are. I just had friends fly them and they mentioned they had to pay a $25 web fee or something like that for every member of their family both ways before they could get on the plane. That sounded bad. I then talked to someone at work who had an awful experience with Spirit and told me to just dump the tickets and go with someone else. I'll have to admit, I was on the fence about doing that because I was looking at $400 in luggage fees with Spirit which is free on other airlines and perhaps some $25 web fee like my friend had to pay.
After coming to this site and reading about how people are treated, I did purchase new tickets through another airline. I just can not risk that kind of aggravation and lack of decency towards paying customers (who leaves vomit on seats for others to sit in!). I'm out a few bucks but I will definitely warn my friends/family not to make the same mistake I did.