No way is it worth it. It's very very nice, but you probably don't have seats that comfortable in your living room or car, so why suddenly spend 10 times (literally) extra just cos you're flying for a few hours. Business class can be justified if you have to get off the plane and go straight into a meeting or something, but individuals almost never pay for this service, it's paid for by your employer. And just cos you've slept on the plane doesn't mean you're not going to get jetlag, you've still crossed half a dozen timezones and no matter how much expensive gourmet food and pudding you put in your mouth and no matter how big the personal TV screen is, you're body clock is still going to punch out when it thinks it's time for bed. So spending (in my case) $10,000 to fly back to Sydney (instead of about $1,200 for economy) is no insurance against passing out at the dinner table and going headfirst into my food a la George Bush.
My Mum can be hilarious if we're travelling together, you can smell the food being served to the first class passengers and she'll say how she must "remember to pay more for my seat next time" (ie sit up front), but her justification for economy class is that those people desperate for status and recognition who pay ten times the fare "don't get there any quicker", "they're still on the plane for 20 hours", and because they're in the nose section, they are, in the event of an accident, "first to the scene of the crash". You guys would like my Mum, she's not a very good flier (nervous, bless her) but she's a right laugh.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz