do what you can afford, my buddy started out back in 04 with an 92 non turbo diesel f350, used it for everything his whole first season, then summer of 05 he bought a left over 04 f350 turbo diesel and it came with a fisher mm2 plow, he sold the other truck and had one new nice truck for about 6 years before he decided he needed another truck, he bought a f250 gas truck for 2000 with a like new fisher mm2 plow thinking the truck was junk and it turned out to be a good truck so he ended up using it for lawns, then he found a someone that needed a starter in their f350 diesel and he traded straight up and kept the plow, then within the last year he bought an f450 crew cab dually for a "personal vehicle, and now that's what he drives around whenever he isn't working. and it has 10,000 dollar wheels and tires on it....so do whatever you can afford to. having a separate vehicle is nice, but takes time to get to the point.
I only have my one f350 diesel now, its a 96 regular cab, its a little tight, and definitely not very comfortable, but for the 3500 dollars i originally paid for it, I can't see myself selling it ever, Its far too reliable, it has done way too much for me to sell it, even if it got 6-7k for it i wouldn't be happy, I would just rather have the truck, its worth a lot more then that to me. I really would like a newer truck asap but its not something i need to buy so i just plug along with with my 1 old work truck. which is 100% reliable, and never fails to start. My friend and I both worked the ever living crap out of our f350's and it doesn't show, his 04 that he bought new has 160,000 miles on it, and has needed next to nothing for parts, just regular maintenance. my truck with 272,000 takes the biggest beating i can throw at it, and continues to ask for more day in and day out. I'm talking towing 12,000lbs wide open up hill for over a mile. I beat my truck like no other. I also maintain it too, so if it needs something it gets it. sometimes with a full load of oak, I've towed 12,000lbs then put another 150 jumbo cobble stones in the bed which isn't light by any means, and it does its job well. I'm not sure what the weight was but i had 2 full pallets of sod in the back of my truck before, seemed heavy. and overall the truck, still is excellent condition despite being a plow/landscaping truck for 16 years and having a 2 yard sander in the bed for 5 or 6 of them, it really doesn't show. so I wouldn't say you are going to trash your nice truck, It's up to you how you want your stuff to look, but I vacuum my truck out when it gets dirty, and i wash it after every storm i plow. actually that's about it, I really don't go easy when loading the bed with logs, I've loaded my bed with wood probably over 100 times this summer alone and hit the back window several times, no cracks only scratches, same with the bed, there's small dings on the outside of the bed, but no dents anywhere on my truck.