How liquid is silver and gold bullion? For a novice investors that is!?

I want to invest in some metals, but I want to be able to liquidate my stash if required (probably $3000-$5000 initial investment). I trust a coin dealer in Detroit will sell me the bullion, but will they buy it back without taking a huge loss? If the price sky rockets, will I have access to full price buyers?
Thanks so much for the quick answers. I’ve read a How to Invest in Gold book and it does say ETF have risks (beyond the volatility of the markets). Does buying shares of GLD and SLV give you rights to the physical elements of Au (gold) and Ag (silver)? We already saw what happened to the banking system, who is to say this won’t happen to ETF’s?

Those are questions I have after reading the section on pitfalls of ETFs.