You can still get new 2012 Ninja 250s or Honda 250 pretty cheap, especially right now. I was talking to a sales guy last week (just about a random thought of trading my bike in for a 2012 ZX6r) and told me that he was selling new 2012 Ninja 250s for $3,999 plus tax OTD. Sucks for people like me who think about trading in a slightly used one in but this ain't cheap hobby now is it? LOL. I know the dealership closest to me has 3 or 4 2012 250 sitting in the showroom. If it's in the budget and you are wanting a new bike look around for a 2012, lots available. I would have been bored within 2 days on a 125, while the 250 is a great bike and I have a ton more to learn on it I am still looking at upgrading soon which was why I am starting talks with sales guys etc (still waiting on my insurance quotes because that is the big decision maker for me on whether or not I upgrade this year)
As for gear, MX would be better than nothing I would guess, but if you are spending money to get gear, get the right stuff for the street. Last year was my first year riding and after this spring I am sure I will be around $2,000 in gear purchases. For some on this site that is very low but for those of us that wear full get most of the time I don't think it is an offensive amount, though I am sure on a budget you could spend a lot less. My original budget was about $1,000. I will have double that by spring and if I get leather pants and the new helmet I want add another 1k on my gear costs.