I had to take a couple chances way back when to get my foot in the door at a few dispensaries. One took a while to pay, but I got it all in the end. My advise is, if it's going to bankrupt you to get burned, don't front your meds. Most of the places I deal with now work on a terms basis. We agree on a payment date whether they sell it all or not. Typically 2 weeks.
It's always hard to find the clubs you want to deal with. You'll meet some shady folks. If you have any people skills, you'll probably know right off the bat. Trust your gut.
You can look at it like any other business. Most vendors in other businesses offer terms to etablished customers. Vendors new to any market may have to give terms to secure a client. The main difference in our little indistry is recourse...and lack of it. If you get burned there's not much you can do about it. Take your licks...tell everyone you know (here too) about your experience with said club...and move onwards and upwards. Hopefully, in time, the shady clubs will go the way of disco, and the stand up clubs will do well.
One last thought: Beware of a club offering a great price on credit. If a person negotiates hard for the lowest price, it's because he/she plans on paying you. If someone doesn't bat an eye at your price (and you're asking good money for your product), it may be because they have little intention of paying you. I had a club offer $4,200 for some Tahoe I was asking $3,800 for. He just needed a week to pay. I turned him down. A month later I read online that the club was burning vendors. They're out of business now.