@Joan Soto All of the above are great advice! If I may add my 2 cents from an investor perspective who looks at wholesale deals regularly.
1) I absolutely hate the "non-refundable deposit" rule from wholesalers. There's just so many possible hidden surprise in a real estate transaction, so for you to have this rule, you must be darn sure that this property will close with absolutely no hidden surprise from your side such as clean title. As a buyer who enter into contract with you, I have no recourse to get my money back if something should go wrong on your side and we can't close.
2) Your comps will be double and triple check by me as well as a real estate agent/broker with access to MLS before I make an offer. Reputable wholesalers will err on the conservative comp number. This is one of the quickest ways for emails from wholesalers who tend to be liberal with their comps to go to my junk email folder or I just unsubscribe from their mailing list.
3) If you're trying to assign the contract and do not have ownership rights to the property. I will want to look at the contract you're assigning to make sure I know what I'm buying because you're selling a contract not a property. If you have taken the property in your name or you will be doing a double closing then you are selling the property so I don't need to look at the contract you have with seller. I don't care how much money you make off the property as long as the numbers work for me.
4) Hard-money or cash only rule. It cost me more money to obtain hard-money/private money financing versus conventional financing, so know that I will deduct this financing cost from my offer.
It's my 2 cents, but due to the above reasons I've yet to buy anything from a wholesaler I've met because once I run my numbers, I might as well just buy a property using conventional lending and put 20% down. I have better COC return and more protection as a buyer from the law. Good wholesalers are hard to find cause they already have buyers knocking on their door begging for their deals.