Went through a similar situation on my 3 ton Carrier last July. The technician claimed it was the fan. After paying for 2 service calls, a new fan, and a new capacitor, I still had almost no cold air. Oops... they forget to mention that the compressor was shot. But they would make me a really good deal on a new system.
I fired the idiot, had somebody else come out that I trusted, had a new 3.5 ton unit installed, and chilled out the rest of the summer.
Definitely get a second opinion from a technician you trust before spending on parts for an old system. And let me know if you decide to replace the fan motor... I know where you can get one (used for 1 day) really cheap.
I assume you’ll be getting a higher efficiency unit - you would have to in order to qualify for the $1,500 - the good news - you can factor a lower monthly bill into your calculations. I replaced my old unit with a Carrier Infinity (18 seer) - and it’s wonderful. Even tells me when to change the filters - when to call for help. Doesn’t brew coffee - but that’s the only downside so far... And it controls humidity levels in the house. For an additional $800 I got a ten year parts and labor total coverage. I’m happy.
sounds like time for routine maintainance. check freon pressure, check filters, make sure ducts and vents aren’t clogged or closed, make sure the blower is cycling properly, make sure the fins on the outside unit aren’t all mashed up, etc.
if you’re using a media filter, make sure it’s not too high of a rating, that can cause air restriction as well.