Look for a lightly pair of used boots cheap. You can score a nice $5 $600 pair of boots sometimes for $200 or in my case get 2 pairs of $200 boots for $20
Boots and helmet are main items on a dirt bike, some people swear by knee braces/guards. I have bad knees and have never wore any knee support and have never had a problem but i don't do a lot of big jumps either.
I have upper body armor but i don't wear it all the time. Mainly for races or if i know i am practicing sketchy stuff, i should be in the habit of wearing it always though.
Neck brace is always a good idea especially if you plan on doing a good bit of high speed stuff
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I love the smell of burning pre-mix in the morning
I don't think I'm a lot dumber than you thought that I think that I thought I was once.