We've found it handy to use "enforced budgeting" 

  Lots of times we booked through a travel agency, and made payments a little at a time.  $200 a month for 10 months is easier to swallow than $2K all at once.  Plus, it's nice knowing the trip is paid for when you leave, so you don't have to cringe when the CC bill shows up the following month!
To answer your other question - we always book the resort first, then flights.  I have lots of airline miles to use, so it's not worth it for us to book a package.  But I'd never get flights, then hope that the resort has vacancies for those days.
In a couple of cases, we found a bargain flight, and an opening at the resort at the same time.  I was nervous booking either, because we needed both to make the trip work.  So I called the resort, and they held the room for 24 hours free of charge.  That gave me enough time to book the flights, then go back to the resort to pay the deposit.
And don't think for a minute that you're getting a bum deal with "budget" rooms.  We only get a suite because it's our one trip a year to be away from the kids.  Even the smallest rooms are very clean, and you'll get the same food and top notch service in all room categories.