Any price us possible, and logically yes it can go below $3500, but in the long term I predict an upward rise.
When buying I'd advise you apply trading skills, and buy at different levels, it's best to get it for as low as is possible, and this could be done installmentally, rather than a one off purchase.
For stability and reliability, to an extent, it is reliable. Volatility is high, so it's not stable as yet. It has it's risks and potentials.
I would not suggest a drop off for 5 or 10 years. Rather they could get involved in the community and make their decisions as they learn more about it.