M10 has potential and it is not a boring motor.
You can see that by looking up its history and different modifications done over the years.
As to $1.50 for M10 - try finding good m10 in a decent shape - let me know where and I will take two. Also they are not that cheap since they are looked after by 2002 crowd.
Again, everybody has a different opinion.
1984 318i w/M10 - restomod in progress :-)
1984 325e - in car heaven now :-(
1991 325i - project / parts car
2005 325i executive edition - daily driver :-)