I started as a service engineer in early '88. It was Australia, so even an intra country flight could be up to 5 or 6 hours. The company never expected me to travel on weekends. I would have to be at airports quite early on Monday mornings, but that wasn't a big deal.
When I was away I received a $70 per diem allowance, (probably about $150+ now days) and the company paid all hotel rooms, car rental, petrol etc. The $70 was to cover my food and drink expenses for the day, and if I could avoid the pub I could afford to eat. If I was away on a long job there was generally no use flying home on the weekends; even if I didn't work the per diem was still paid. I did spend an amazing amount of time away from home, but I was young, and the financial considerations weren't too bad, especially as the per diem was tax free.
After about 5 years I moved on, never intending to get back into a travel mode again. In 2000 I was dragged back into a traveling mode job, at a fair bit more senior level. This one included quite a bit of international travel, and I was on a plane at least 35 times a year. For this role there was no per diem. The company paid my expenses and that was it. I was rather amazed how the company treated their traveling employees. International travel - make sure you leave on a weekend. Intra country travel- here, we've booked you on the red eye.
So I made sure that I got a receipt for every purchase I made. If I bought an apple from a street vendor in Tokyo, I got a receipt; a pizza from a local shop in Bologna...a receipt. I'd come back with hundreds of receipts from each trip. Hand them in, and let the office staff sort it out. I eventually got "called in" to explain myself. I just put my foot down. Explained to the company if you wanted to treat me like a serf then dumb insolence was going to be my standard response.
As to the question about whether you'll get paid more for being a traveler, I doubt it. Just don't let the bastards treat you like crap and stand up for yourself.
Never let the bastards get you down