18 640i GT Maintenance

[z.runobx]

Have a 2018 640i GT that went in for some maintenance and they found a couple issues that just seem like a huge price tag that I didn't expect.

There seems to be a coolant leak, which i know is common, but they want to replace the reservoir and hose. They say to do both and that the hose is causing the price to be a lot because they have a lot of labor. see pictures. $3k for this.

They would like to replace the rear output shaft seals b/c they say they are leaking. I do not know much about these. Charging $2k.

Also they says the transfer box bushing is leaking, which looks like it is. charging $777.

My general question on all of these are do these these need to be done, how unreasonable are these costs (i know BMW repair costs are always inflated), can i do any of these repairs myself (after looking at youtube videos, the reservoir tank seems like that's probably all i can do, i am very good with my hands, i just don't have the tools/equipment/jacks/etc.)