To kill or let die

Hello.
I have a sick dog.
A 13 yr old Schiperkke named T*****.
She is absolutly the love of my life. She is also a service dog.
Now she is at terminal end stage CHF, chronic Heart Failure. Her abdomin is round and hard. Bloated. There is no cure for the condition, anyone whos seen this knows how heartbreaking it can be.
   Now, at her age. some say,"Let her die" Or "Put her to sleep, $75+.
CHF is often a long painful death. So I call all local Vet's. They want me to schedule an appointment, $50+, Then they want to examine her, $50+. After that, X-rays, $150+, Bloodwork $50+. all to say either: "She has a tumor and there's little we can do", because of her age...and "we could opperate, but she may not make it thru" $2k+.
BUT if there's no tumor, and it's CHF (Which is OBVIOS) I mean they are professionals and see this stuff everey day, correct? CHF, Untreatble. But w/medication we can slow her death down....for another $50 extra. And maybe we can drian her. $100+ because we will need to do it in stages,,,and it's not healthy to do..but it can relieve some of the pressure on her heart and lungs, meaning she could breath a little easier.
   So, I go the $50 for the examine and get the pills for CHF, They will not hurt her if she has a tumor. But she is getting bad, worse, can hardly breath. They're not helping.
    I call all the vets again and explain, begging that they please release some fluid from her abdomin. I have $118 to my name I will give them. Guess what??...Read above, all over again. THEN, and only then, will they consider "Draining".
    So, I tell them, I am going to stick a pen in her side and let out what fliud I can. They all get upset and rightous, saying,"It could kill her".
   What is wrong with this picture?
Is it I am not giving them $100's for diagnosis, x-rays, and pills for a TERMINAL illness? OR, is it the risk she might die, without them getting $75 to euthanize her?
OR, do they actually care about the dogs health and well being?