To Anyone Interested;
First of all thank you to everyone who replied to my post.
After changing the Transmission filter and oil twice, I still had the same dreaded shifting problems. Changing the filter and oil only delayed getting the transmission rebuilt.
The MB dealers wanted in Hawaii wanted $1800 for a rebuilt transmission (with a trade in snd a $3000 deposit. If they determine that your core is no good, kiss your deposit good bye) and offered a 30 day warranty if you install it yourself. I think the warranty was 2yrs if they installed it, but you have to add in the cost of the removal and installation. I think that would drive the cost up to more than $2000.
Not having over $2000 to spend. I found a mechanic to rebuild my transmission (using only OEM parts) and he also installed it for $1750.
Now I know why the seller sold me the car for $3500. Oh whell, the car works fine otherwise. Hopefully it'll last me at least 5 years. (I've owned it only for a year).
Good luck to anyone who has the same problems. Hopefully your repair is not as costly as mine. Definitely check your filter and change your oil before thinking about getting the transmission rebuilt.