If you're not familiar with the newer emissions engines, do a little googling. Any CAT ACERT engine is basically junk, they have huge issues, often, and in many cases the problems are literally never resolved. Sure there are some that live a long time with little trouble, but it's the exception rather than the rule. I've been researching Cummin ISX, and the sweet spot seems to be about 04-07 with EGR but before DPF, earlier engines should have been more reliable but had cam issues among other problems. The EGR engines are a bit annoying with EGR valves and coolers but all in all seem to live and perform much better than engines built before and after.
CAT alluded to the problems of making their engines meet Tier 4 final as the reason they dropped out of the on highway market, in truth the disaster created by the ACERT engines I believe forced their hand to bail, they simply couldn't keep enough of them running to make it viable.
The prices of diesel engines has more than doubled in recent years, it occurred to me just yesterday that a fair bit of that increase is probably their expectation of warranty costs based on the track record of high failure rates in many components, turbos, EGR systems, sensors, common rail pumps and injectors, DEF systems, etc.