I dont know,
I am kinda a master of low buget riding. I think if you dont race a bike, even a 2 stroke MX bike can last for years with very little $ . Just make sure the fuel is mixed right, the tires, chain and sprockets are ok, and put good tranny lube in it once in a while. I suppose a good education about how to take care of a bike is worth loads of $$$$.
Riding gear IMHO is more or less a one time investment and can last a very long time. Take care of your boots, thats about it barring major crash damage of like a helmet. Your looking at a good 500 bucks right off the bat though.
Hey, many used bike sellers will throw some if not all the gear in too! Especily the "got married, have kid, bought house, selling toys" chumps :) . I get my best deals off those guys!