If a journalist went to Riyadh this week and stayed for 2-3 days, the flight would cost roughly around $1400 - $1600 USD (from LA), and a basic room at the Four Seasons in Riyadh is around $700+ a night. Meals are probably included as a guest of the state. That is a lot of money to be taking from a government-backed entity.
This is why real disclosures are needed when press lets companies pay the way. It's okay to do that (some outlets can't afford to send people to an event) but disclosing it shows the readers that you respect them enough to be transparent and that you work for them.
Your motivation as a journalist is to inform/serve the public, not the interest of your hosts/business partners. If it's not, then you are a marketer/PR flak, not a journalist. PS: If my numbers are wrong, please correct me.