Boss asks employee to spend $2.5k on work trip to be reimbursed later, employee resent the upfront cost and doesn't trust they'll get the money back: 'The business is hugely struggling'

Spending money at work is something you should probably avoid where you can. Sure, you have to buy lunch sometimes, or coffee on the way in, or even minor expenses while you're on a work trip. But no job should be asking you to shell out thousands of dollars at a time, even if they tell you you're going to be reimbursed later. The way things move through a company, it might be months before you get that money back. Meanwhile, you're upstream with no paddle, out thousands of dollars of your own money. Not many people have that kind of wiggle room in their budgets. That would set back the average worker, even if that money eventually made its way back to you. So it's understandable if you would bristle at this kind of request. After all, they're the company. They should be the ones with the money. 

It's also impossible to totally trust the company you work for. They might have a good history with you, and you might be loyal to them for good reason, but you can never let your guard fully drop, especially with money. Things can change in an instant, and it might come back to bite you when you least expect it. You never know when they're going to hit hard times, and you're going to end up paying for it, sometimes literally. It's better to avoid opening your purse at all, lest something happens while your head is turned the other way.