Hmmm,
Brings to mind that my neighbor saw my backhoe and asked me to come up to dig a hole for her old horse.....
In no particular order my used ford blue 7500 woods BH with pto pump has:
Buried pets
Replaced underground power lines (after some idiot on a 3430 ripped it up with the FEL)

Numerous drainage projects (sure beats using the FEL)
Cleared large boulders (dig hole push it into hole)
Saved my back on many occasions.....
And made some really big holes out in the field as I learn to run it..
Seriously, I got a decent deal on a tired but working BH and jumped on it. I need to learn how to replace pins and bushings but meanwhile I run the pto at idle and don't push it very hard. I have never had a problem completing a task even at this low power setting.
This summer I intend to buy the 4 pt mount as the 3 pt mounting really seems to stress the tractor even at the low power setting. I know when I get the pins cleaned up that I will start pushing the BH. I want the mount stronger and safer before then.
If you can afford it, get the BH you will enjoy having it.
If you really need to rationalize or justify the purchase, put it off for some time and pay someone else to do the work. One of these three things may then happen:
1) you run out of things to dig and thus save money in the long run
2) you eventually realize that you should have bought the BH attachment. Hopefully enough time has gone by so that you can find a used or better or less expensive choice.
3) you soon realize that what you really need is a small excavator and you are pleased that you saved the BH money for that larger expense
Again, my .02 is that you buy the BH if you can swing it as it is fairly doubtful that you will regret it. I also am one of those that encourage buyers to buy as much tractor as they can afford.