Figured id chime in here. Diesels are definitely not for everybody. And im surprised of a lot of the bad luck people have had in this thread. Of coarse forums are manly for people having issues, and solving them..
Me, Ive had many ram cummins trucks, personal and work/business since they decided to put em in the 1st gens. since 93 Ive had 10 personal and add another 10 to that for work employees ect.. With the exeption of an 07 and an 11 all of my personal trucks have manual trans. They've all seen about 150k of mixed family truckster/towing about 10k-15k from time to time and off road use, with the exception of my 03 and 05 which each have/had 250k and the 05 which I still have has 277k. and presently also have a 13. Most all of them had 4.10 or 3.73 and the 13 has 3.42. Of the 10 personal trucks ive had 2 were modded pretty heavily, and ran like a bat out of hell and was just absolute blast to drive, but out of all of my personal trucks, Ive had 6 warranty claims. and one of em was for the radio in my 13.. fuel line rubbed on filter housing on the 97, 03-05 each had front hub assemblys/bearing while in warranty, front axle ujoints on 03 and 07 and throwout bearing failed on 13 ( at 12k ) gave me a new clutch on that too. Most of the 3rd gens I did do ball joints/tie rod ends at some point and u joints all around, which are to be expected regardless of gas/diesel or brand as it is typical maintenance. My 05 I did pull all the injectors and sent them out to be rebuilt when the first one went out at 230k. All have seen an avg of 19-20 mpg. Even the 07 and up trucks. The worst being the 07 6.7 16mpg and the best being the 05 22mpg. and around 12-14 towing. Now as far as value goes, the initial diesel option cost is more to have them, however, when your done with them, you get it back, and then some. The diesel trucks will hold there value usually more than the initial cost when comparing to a gas truck.
As far as work/business trucks go, they get used and abused, just as they are intended to be. Most of them autos, loaded with fuel tanks, tools, pulling trailers, lots of idle time and off road constantly, and still basically only need typical front end wear stuff, ball joints, ujoints ect.. and definitely always stocked lift pumps for the 24v second gens trucks, shift solenoids, water pumps and idler and always had a spare hub assembly for them along with track bar bushings. Never had a single driveline failure engine or trans in any of them. Personal or business. Only had one work truck (99) lose an injector pump (twice) for a pinched fuel line starving pump for fuel.
Now, with all that being said, I work with diesels of all brands constantly work with heavy equip/mining for a living, do all of my own maintenance and repairs on my personal trucks and all the work trucks maintenance/repairs other than warranty are done in house for the most part.
My experience with diesel ram/cummins trucks, personal and work, is, as long as theyre maintained properly they will yield you the best bang for the buck and if you can do any of the maintenance/repairs yourself youll be that much further ahead. But most importantly, the power and reliability is the main reason I stick with them.
When repairs are needed, they can be pricey, especially when having to farm out the work. Clean fuel and fuel filters are your friend with a diesel. Ignore the fuel system and typical maintence on a diesel of any kind, and you wont have much luck with them. And if youre buying one to go to the grocery store once a month you will not be very happy with it..