If there was something material that changed the pricing they might not be able to get it back to where it was originally though.

Otherwise, the training materials such as books, podcasts, webinars, etc. are so floofy and sugar-coated that I most definitely could have accidentally jumped off a cliff!

We need to know the details of what they were installing, the location, the cost of materials, etc.

I also discovered some excellent YouTube channels that discuss test material and sample questions, which I watched regularly.

Concealment does have a material impact on pay back. 

It's the labor details that cost you, NOT the materials. 

If development is allowed in the flood fringe then it has to meet certain criteria like it must be a certain elevation above the BFE, at least 1 foot, maybe more depending on the location, and it must be built with certain materials among other things.

I provide tenants with a form to request any improvements and it spells out exactly what they are doing, what material will be used, who will do the work, who pays for it, what happens to it when they leave, etc.

Just like you would do with any non-family contractor working for you:- get them to complete Form W9 for you, as you will need their SSNs- have them provide receipts for materials/supplies and keep those receipts- have a written labor agreement (how much and for what) - pay for materials separately from labor- make all payments electronically rather than cash so you can trace them- pay out of your business account, not personal- issue them 1099s next year if you paid them $600 or more for labor (for the whole year, not per job): https://www.biggerpockets.com/forums/51/topics/1167632-expla... 

He was a good guy, totally honest, and I bought a few good buys at tax sales after going through his material.