He is doing what a good employer should, providing what his employees need to do their work.  I'll tell you the same thing I have told several men I have worked with:  DO NOT bring your own tools to work.  It is the employer's responsibility, not yours.

If you are a partner that is different, but as an employee keep your tools at home.  I've seen too many men bring their own tools because they were more comfortable with them, didn't want to bother the boss, didn't want to look demanding, etc. Hogwash.

It is the employer's responsibility to provide you with what you need to do your job.  If he only wants to provide you with a Chinese adjustable wrench and hammer the results are his fault.  If he wants you to be effective he will provide what you need.  You wouldn't buy your own tractor to drive, would you (if the answer is yes, ever consider moving to SE Illinois?) 

Make up a list of what you need with an estimate of cost and get his approval.  Then go get the tools you need and use them.  And the first time someone gets into your tool box and doesn't return something or doesn't put it where it goes lock it up.

$2000 - $2500 is really pretty reasonable for a service truck.  I set up 2 for the propane business over 10 years ago and we had $2500 in each one before we put parts in them.

Agboy's comment about not "spending that if you have a nice shop at the farm to work in" caused me to set and think. Oddly enough, the folks I know with the nicest shops have the best equipped field service trucks.  After spending 20 years of doing on site repair I cannot get a truck as equipped as I would like.  I have finally had to admit to myself I can't carry everything unless I get a school bus and make a rolling shop out of it.