Okay --- Here's another "thought" or scenario to toss about.
Let's take the guy that started the capenter tools / nails truck/van.
He gets a backer or he borrows against his house - or he sells his boat and buys this "van" and 25K worth of inventory. He knows what inventory to buy - because he worked in the industry - so understands the wants and needs of his prospective customers.
Rule #1: YOU'VE GOT TO KNOW YOUR MARKET!
Now... He starts out with a lot of "risk". He's got inventory - he's got a van - he's got overhead in insurance... fuel... time... and payments to make.
Rule # 2: He is WILLING to take the risk and he is willing to lose it all and start over.
Okay -- so he does his homework and figures out a economical "route" from job site to job site. He is going to have to spend a LOT of time stopping and talking to the work guys. He needs to schedule this when THEY can take the time - or he has to be willing to WAIT a half hour or so - so that he's not disturbing the production. TIME IS MONEY.. but he is also making an INVESTMENT with his time at this point.
So the guys start to visit his truck -- he has the right stuff @ the right price and he has it NOW... if he comes back on FRIDAY (Payday) they'd buy "X" hammer... or that new compressor... Could he take payments? Maybe $50 a week?
Lesson: There are people out there called FACTORS. They will buy your "receivable" from you. There are rules and details here I'll not explain - but you'd need to hook up with the FACTOR FIRST to see what they do and what they want/need from you. FACTORS pay you for your invoice - and then you collect the money for them - or they might collect it themselves - but they pay you up front for the invoice - giving you the money you need to replenish your inventory. There is a COST to this -- but it can work out very well. You can sell your stuff on "time" - so getting sales you might not otherwise get... and establish that "supplier customer" relationship.
You have to come around on the route every "X" day... and at "X" time when possible... you have to be RELIABLE. This way - when customer A needs nails -- he knows you're going to be there on X day... If you don't show - he has to get his nails somewhere else. You also should be "on call" -- be available to deliver X goods any time at a moments notice -- and BE HAPPY TO DO THAT! Even if it means you might actually lose money on the transaction but you KEEP a customer! You might have to drive all the way across town to get two $30 hammers... which makes you up at 5:30 AM the next day to get them to the guy before he starts work... OH WELL... that's what you do!
Are you going to get rich? Probably not... but if you're really clever - and your business is well run... you might end up with two trucks - and then 3 and then expand to the next town... and you might add Ladders to your mix... and you might end up in the office instead of driving and delivering... and you might be 50 before that can happen... and you might be carrying your own receivables instead of selling to a factor.. and your kid is the warehouse manager... so all's good.