I just ready this in an email, a job offer which requires some PI work!...with the following disclaimer:
"To complete this shop, a $50 deposit is required to cover the cost of the GPS tracker. The deposit must be sent through PayPal to email@example.com. The deposit will be refunded after the report is finalized. After making the payment, please email your Transaction ID to the contact information below."
Lemme see here....pays $30, but I have to deposit $50 which I "might" get back, when my report is finalized.....
It's not that hard and they guarantee your money back as long as you can verify you dropped it off. The GPS has verification and it matches your shop time. I did a go verify just for extra insurance. The MSC is great and I got my money back very quickly. These take less than 2 minutes to do and are very much worth it. The trackers are very expensive so they didn't want people flaking on the shop which is why they ask for the deposit. I absolutely trust the MSC that if something went fishy, I would get my money back. They've gone to bat for me before with weird shops.
I've done several of these and have not had a single problem. They pay well for almost no work.