And when your alternator goes ,or fuel pump,Clutch. Those cost of repairs are in the Thousands. BMW are nice . But your compairing, Plum to an apple. If you want to compair BMW's to a Charger or Challenger. Try M3 for the challenger,and a 5 series for the Charger. They are the same weight class ,and car class.
BMW 135 is in the WRX pocket rocket class.
Unless your BMW is more than 4 years, there are absolutely no costs for any maintenance or services. BMW is one of the few manufactures that have 4 year/50,000 free maintenance plans on all new cars. The only thing you will have to pay for is gas and tires. So over the first years of ownership between a 135 (or any BMW/Mini) the service cost will also be cheaper than your Dodge.
This is one reason why I lease my BMWs and get a new one every 3 years. I've not paid one cent for anything other than gas or tires since I got my first BMW in 2001. Even stuff like wipers, all fluids and brake jobs are free within the first 4 years.
Now I will grant that a BMW older than 4 years will get expensive to own. A brake job on the 545 I used to have would've cost $1,200 once outside the 4 year window. Again, this is why I lease them, not to mention cheaper monthly payments.
Ok, I will grant you that the 135 and the Dodges aren't competitors. I was just strictly talking about performance for the dollar comparisons. Not practical considerations. While the Dodges are more expensive than 135 base models (which include all of the performance) they are more practical for a family than a 135. And don't my take my talk of BMW as trying to put down your Dodges. They are great cars too. But I feel about BMWs they way you feel about Dodges.
For a more equal comparison Motortrend did recently compare a 135 to a Mitsubishi Evo and they like the 135 better.
Now if you want to compare the M3 to a Challenger, that's not really a valid comparison either. The M3's is in another world compared to the Dodges. The M3 will go 0-60 in 4.1 and qtr mile in 12.6 @ 113 mph and did Car and Driver's lightning lap in 3:06. About 10 seconds faster than the Dodge. But the M3 does cost a lot more than the Dodge so it should be a better performer. In various comparison tests, Car and Driver has recently picked the M3 over the Porsche 911 Carrera, Nissan GT-R, Porsche 911 Turbo, Lexus IS-F, Mercedes C63 AMG and Audi RS-4. IMO it's one of best cars in the world right now.
You mentioned the 5 series. While not as a good as a 3 series, an ungoverned but otherwise stock M5 with the 7-speed SMG can do 205 mph. Numerous videos on the Internet confirm that.