Final results of what's been wrong with x5 need advice

[sarnomel]

Thanks to every one that has responded to all of my threads, there have been so many. I finally found a good indy and the results vs what the dealer has done and said had to be done are astonishing because I feel they are very different. I believe my last thread was that the dealer said that my service enging soon light turned out to be my torgue converter needing to be replaced at 3700 and I believe that said that they may not fix the problem, therefore it would need a new transmission after that. Well, I took it to the new indy that I was referred to and these are the results and what they fixed and also what they said still needed fixing. This is kinda long. It reads: Check engie light is on. Pulled codes in the main engine computer and found codes for the auxilliary fan activation also codes in the ags transmision for torque converter clutch slippage. Checked level of fluid in tranny found to be 2 1/2 quarts low. fluid is very burnt with metal particulate inside. Trans needs to be replaced. Checked the output stae on the fan by checking signal to the control module in the fan, fan is switching duty cycle normally but fan itself is not activivating. Vehicle needs fan.While driving heard loud ticking noise, found fan clutch is making noise due to it being bad. Replaced fan clutch. A/c blows warm air, the dealer replaced the blower motor without needing to found it needed to replace auxillary fan them retest system. Replaced auxillary fan working normal, ac is still blowing warm air, need to evacuate and recharge then retest, evacuatd and refilled a/c system now it blows at 38 degrees. Clunking noise in front end, dealer told her is was the steering shaft needing replacement it's actually r front lower control arm, replaced it and no noise is present. So my total bill for 2 fans, control arm, labor was 1,915.37 which I did because they said these fans could make my car over heat and ruin my engine. I didn't have them replace the tranny and this is where I need advice the quotes I'm getting for used tranny (which i don't think i want) to the pre manufactured (I think is how you say it) are from 4500 to 7000. Is it worth it to fix the tranny or try trading it in. I have my eye on a 2005 x5 4.8 with 20000 miles. I love this car I just think I have a lemon. Any ideas?