Need Help With Putting Sparks Down

Hi everyone I hate to do this as its my first time doing this ....ive tired to have a yard sale to raise money for this but it didn't turn out so well ...so now I have been told by many people to do this. So I'm gonna do this and hope it works ....Sparks is 14 years old and is very sick with liver cancer I have had him 14 years and now he has been diagnosed with liver cancer that has now spread throughout his body ...some people are saying wait it out and let him go on his own and others are saying it's mean..as his owner i think for him would be best to put him to sleep and outta pain I can't afford to keep bringing him to vets as I have put out over 1000.00 already and can't afford more I wish I could I fell so bad money has been very tight for us as i have moved back to windsor do to my parent health...and it was what was best ...my heart is so broken knowing there's not much I can do for him as of right now not having any income at all ....please if u can help i will forever be greatfull because of his wieght it's costly...it's gonna cost about 550 to put him to sleep of have his ashes back ...as he is my child furbaby ...I ask please please help me