I'm told that i have a dented tranny pan and that i should have it replaced for $800.

If I was out of transmission fluid would the car still run? How do I know how serious this is?

if you were out of fluid, the car would run for a while, then I imagine you'd get some serious lock-up and the car wouldn't move.
Sounds serious to me, but $800? hmmm.....

should i get the transmission fluid changed and see if it leaks? I don't see any leaks but maybe its empty.

I'm guessing that there is where the concern lies.

both. I just got a quote of 400 for the pan, 40 for fluid, 70 for filter and 250 for labor.

wouldn't function. If it was severely dented, it might impact the filter, but it would have to be a major dent.

I would be concerned about the quotes you have received - the $40 for fluid is WAY LOW! It cost me $15 per liter, and it takes like 6 to 7 liters of fluid with the filter change. Sounds like they are not using the proper fluid - it needs to be a ZF (tranny manufacturer) approved fluid, not universal ATF stuff.

You'll have to get under the car to see how serious this is, but any seepage of fluid from the pan gasket area needs to be addressed. These trannys are sensitive to low fluid and are expensive to replace/rebuild.

thanks - I bit the bullet and replaced the pan, changed the filter and fluid.

to repair/replace. Likey made a good, safe choice. I would have done the same. I'd rather spend extra on maint and repairs than get stranded or hit with a huge bill because I tried to risk or push it.