My two cents worth is, if you can't afford the upkeep, don't bother dying the hair. (Unless you have greys. Which I am sure you don't cause you're and 87 baby like me )
I would really say the best is to cut off the jucky dyed parts that you don't like and stick to natural.
I'm in Asia and well everyone is telling me to go blonde although I am a natural chocolate brown. It's taken me so long to get back to being all natural. It depends on the industry. Koreans love them blondes so I'm kinda thinking about taking the risk, though I can afford the upkeep.
Sorry for going on a tangent... Just had to share.