A/C freon leaking, proper way to fix & think got ripped off on so called 'estimate'

Took my 85 Eldo Cad, with only 120,000 miles, keep in good shape & knew it was leaking Freon as no cool air from end of last year. If needs a part, I'd get & my neighbor usually put on for me. He didn't have gauges or probably would've put my Freon in. Also, they just moved 3 wks ago & sure will miss them; SO tried this supposedly 'ok place'. HA. As knew had Freon leak. Believe manager is a rooked Christian', to make as much $ as could. I didn't see any diagnostic machine hooked up, he didn't give me any printout of any sort; told him codes 30, 38 & 52 were coming up. He had car in work area about 30 minutes & charged me for 1 hour's labor. SAID? Put 3 lbs (who knows) of Freon in (had little in there, but not much & as said, slow leak, blowing just air. I asked if they put ultraviolet in to find leak & said NO, I'd have to drive a while & see how long A/C stayed cold 1st, THEN COME BACK TO PUT IN ULTRAVIOLET TO FIND LEAK. (Why I came in 1st place!). He proudly stated: my comressor was bad;(but it wasn't 'bad' when had tuned up 3 1/2 months before, & in wreck after leaving mechanics that night of getting it tuned up, running good, til guy pulled in front of me & I hit him apx 25 MPH & police gave him a ticket & now, my neck is all puffed up & killing me, look like Hulkette.) Compressor fine per mechanic apx month later when had to go back for him to put in plugwires. I asked mechanic then if hurt compressor or anything else, said it was ok. Mr. Wonderful, at this business came in about Freon, rudely continued: that I needed "manifold assy, drier & orifice to warranty their Freon job IF they did. THEN TOOK THEIR 3 LBS OF FREON OUT, AFTER HE HANDED ME AN ESTIMATE OF ALL, $1100 plus tax to fix (A BREAK, he said). Which I thought was unbelievably high. He watched me write check & handed to him, THEN said, 'I don't take checks'. He was huge, had small bumper sticker size sign behind him on lower wall stating 'no checks', that NO ONE could have ever seen, behind cash register & HIM. I dumped my purse for his $43 charge searching for cash & change to pay him, down to even $10.50 of quarters, pennies & barely had it. ($1.20 cash left over). I told him I didn't have a debit card and didn't want one. I WAS FUMIMG BY THEN. He was on phone for most of time getting new windows replaced at his home. Very rude, for a' so called' Christian, with 'God loves you' stuff all over. Yes, God loves me, just to have hunted forever for his $, & sense enough to get out of there; but don't think even He would like him & way acted, with this illustrious estimate. I thought was rather on the HIGH SIDE. I'm disabled & on fixed income & told him that when came in & in wreck 12/19, bumper, fillers & PS fender is smushed due to guy pulling in front of me, etc. Not my fault. He, Mr. Wonderful Manager, said: ' your car isn't worth fixing', just to top off! Just to make this ole redhead madder. Got in car, they had A/C ON & it was blowing out dark gray spongy stuff & dirt from vents, a first. I cut off A/C & went & got guy to ask him why doing that? He shrugged, no answer, so asked HIM to clean is up, JUST HAD IT, THEY GOT ON MY LAST NERVE; LEFT burning up (from heat and being upset). What an experience. Also, after this wreck, seems like idling a lot higher. Would you all know why? Would an impact cause anything else to not work properly? What do you all think? I sure would appreciate opinion from a REAL mechanic/person knowing about A/C & CAR stuff for a nice lady. Thank you for your time & help. P.S. What if you live where there are VIRTUALLY NO MECHANICS that know about classic cars or care. I finally found a salvage yard out in the country with an '85 Eldo, but think their parts have to be accepted by person doing body work, right? For insurance purposes. Sorry my question is so long. I love my ole Cadillac & it rides very smooth, but is IDLING high, so some unknown reason. I think it's worth keeping. I think they are JERKS.