if you do the work they are fun to work on. between realoem.com and several online bmm dealer and pelicanparts.com it is easy to find good parts at decent prices. and the diy support here makes a manual almost obselete.
that being said bmw require much more maintenance that your average honda. If you buy a car with 100K it will need more than $1000 worth of parts if the previous owner did not do the maintenance. Just a lot of dumb stuff breaks that you rarely replace on other cars. Expect to rebuild the complete cooling system and suspension and you will have a good baseline to start with.
I expect you can still find good clean e46's that have been adult owned for a decent price.