A 44 cal (magnum) is an 'original' Vaquero as opposed to the New Vaqueros which are only sold in 45 Colt and 357 Magnum. $400 will get you a decent, 'unimproved' example. It is still possible to find these new. Expect to pay a minimum of $500-575. Strangely, stainless models don't seem to command a higher price than basic blued models.
10 bucks
100-500
Depending on condition, about $350.
100-400 USD or so depending on specifics
50-165 or so
50-175 USD
RUGER PISTOLS ARE GOOD GUNS, ABOUT $600
100-400 USD
You need to contact Ruger. You may have a prototype
10-200 usd
50-200 USD
50-250 usd