No it is not too late, although if you have waited this long you may be sad because the price did a x4 in just this last 8 months. I believe in time a 10k bitcoin is not very hard to achieve so no it's not to late, not this time at least.
I would wait for the next 20% drop of btc, but I agree now is always the best time to buy btc. and 10K usd is only 2.5x away. so it will reach that 10k in 2018