Earnest money is a real cost and it varies more by deal size and seller sophistication than by anything else. On a small commercial property, say a six unit or a small retail building under a million, earnest money in the 5k to 10k range is common and it is often refundable during a due diligence period. On a 5m apartment building a seller with a broker may well want 50k and want it hard after 30 days, meaning you lose it if you walk. That is why most people who start on the commercial side start small.
The line items you'll actually spend money on before any deal closes:
Attorney review of your purchase contract and assignment language. Commercial contracts are not one-page forms, and a few hundred to a couple thousand for a good template you reuse is money well spent. Rules on what a wholesaler may do differ by state, so this needs to be a local attorney.
Data and lists. Commercial ownership data services run anywhere from about $50 a month for basic property lookups to several hundred a month for the ones with lease comps and sale comps. Some states don't publish sale prices at all, which changes what a subscription is worth to you.
Phone, mail, and skip tracing. Direct outreach to owners costs real money per contact.
Earnest money on whatever you tie up.
The thing that catches people from the service side is that you already have the more useful half. You know operators and you know buildings. What you need to add is the ability to read a rent roll and a trailing twelve month operating statement, because commercial buyers price off income. Learn to build a simple net operating income and cap rate calculation in a spreadsheet before you spend anything on software. A general real estate license may or may not be required depending on how you market contracts in your state, so ask your state commission directly.
