It's not that hard to rebuild a cylinder. I sometimes leave cylinder and hoses on loader and remove the rod and piston to replace o rings.
Then take rod and cylinder to hydraulic shop. I have two hydraulic shops near me to pick from. Both will sell parts. I can usually buy all the o rings I need for around $25. My hydraulic shops are also a good source for information. You can also buy spanner tools from ebay or amazon. Hydraulic shops charge me around $75-90 for a rebuild. I had some cylinders I gave up on and went to international hydraulics and bought aftermarket cylinders for around $150. Be careful and make sure you get the ports in the correct place. I've had good luck with international hydraulic cylinders.
I had no choice, had a cracked cylinder. That cylinder the ports were in a different location and had to get it from factory, $450.
If you have a loader or backhoe, better learn how to rebuild cylinders. They will sooner or later leak.