As a newbie H1 owner, I can tell you that those numbers are astronomical, almost paranormal...LOL
It has been two months since I purchased my H1 and I have performed all the maintenance, A,B,C plus more and it was a few hundred dollars. I relocated my PMD just in case, cleaned my battery terminals due to an unexpected electrical issue. I thought I needed a new right front halfshaft so I ordered one from Dave (HPG). After taking the access cover off to access the 9/16 bolt that holds the shaft in place, I noticed that it had backed out. I tighten it and no more halfshaft noise. Thankfully, HPG took the shaft back. I then proceeded to remove all the wheels off, change the gear hub oil and tighten all the bolts. What I' am trying to say is, if you buy a truck that you know needs work, yes, get ready to pay for the work if you cannot do it yourself. Maintenance is not much more than any other truck, you don't have to change the gear hub oil and differential oil constantly. If you maintain your truck there will be less of a chance for things to break. Two things I had to repair were my CTIS tees and my Speed sensor, both items cost less than $100. The rest of the stuff like my Rhino tire carrier, spare tire and PMD relocating kit were extras but did not need to do right away.