500 is reasonable from someone you don't know.   If you lived near me, and since you've been on  Anandtech for 3 1/2 years, I'd do it for about $100 for you - unhauled. (And, I'd give the $100 to my kids who would be forced to do all the labor - carrying all the logs) Looks like a very simple job (although a couple of the first cuts would require a little bit of knowledge to avoid further damage, possible injury, and/or pinching the blade).   Are you allowed to have bonfires there?   (good way to get rid of the branches)   I don't think it'd take longer than 2 hours to reduce the tree to a pile of logs and clean up the mess.