1990 525i with 240k miles - has my auto tranny bit the dust?

It started out several months ago with slipping between first & second gear.
Today, it was slipping between all gears then just stopped going forward
altogether.

The guy at the shop said he didn't think it was worth dropping the pan but
was investigating other options.

Should I scrap the car? Get a used tranny and do it myself? Rebuild this
one?

Any thoughts are appreciated


.