When I first went into business about 4 years ago I drooled over owning all that stuff, About a year ago my ex boss was going out of business so I asked him what he would take for his pulling equipment, he said $1,200 so I grabbed it right away, it's a greenlee 4000# tugger, 686 package, has the box, extra sheaves, pulling clevis, 3/4" rope and many other extras that he let go with it.
I had my supplier price out every thing new and it was over $7,000. It may be 30 years old but has been well maintained, I've used it for pulling in quit a few undergrounds since I bought it, at least I don't have to worry about a guy running a back hoe ripping the wire apart. he had a hydraulic bender up to 3" ridged but I remember it not working all that good when I used it so I didn't buy it. I admit I wouldn't have bought it if it wasn't such a good deal but it's nice to know I don't have to worry how I'm going to pull the wire when I have a long pull to do.
Back to your question, I don't know when it makes since to invest into something like that but I know I have invested into allot of equipment in 4 years, some I have only used once but I feel I'm still in the process of building my business so when I need it I have it. Also I'm a one man operation (for now) sometimes subbing out to others to help me but what ever I can buy to make it easier for me (in my budget) then why not make my job easier.