First a little homework.
689s are relatives of the 669. Those have been made since 1989. Members here have them and describe them as rock solid and accurate.
No other time period is of consequence as far as quality goes. Conventional Wisdom to the contrary this line is a solid one.
These are still being made and sold in Brazil by Taurus.
Had the 689's brother the 669 in stainless steel. Locked up solid, no end play,timing was excellent. Had the 6 inch barrel. Nice revolver.
Problem was I needed a defensive concealable revolver that was shorter in tube length and sold the 6 incher for 4 inch model Taurus 65 & 66.
Have sent thousands of rounds of both .38 Special or .357 magnum down range with the Taurus 65 and 66. These are over twenty years old as are many other staff and members revolvers. So durability and longevity are the bywords.
Two caveats. Don't shoot a lot of the super hot 125gr. loads through them. Like S&W K frames battering can cause excessive wear and tear on them. Flame cutting of the forcing cone can happen along with timing and lockup troubles.
There are 125gr. through 135gr. light .357 magnum loads put out by Federal, Remington, Speer,and Winchester that have less recoil,punishment to shooter and gun, lose only a few feet per second in velocity.
Hogue or Pachmayrs would be a good idea. I changed the wood grips for the rubber ones as fast as I could after a box or two of full fledged magnum rounds.
689s were stopped from importation because the model 65 and 66 taking the 669/689s place. This was because of the what the market was buying. Not due to quality troubles. Gun companies,especially Taurus, change their lineups drastically at times.
Yes, it was Taurus who manufactures the guns. No one else.
$299 seems about on target, but after consulting the Blue Book of Gun Values and other sources the price seems right. Gun parts should be able to be still had from Taurus. If not www.e-gunparts.com or www.brownells.com will have them.
If this is a used gun, it functions well, or a certified gunsmith can check it out, you have a good deal in the making. Haven't seen the actual revolver, but it sounds like a good deal.
Regular .357 loads of the 158 gr. persuasion should cause no troubles.