I don't have enough info to tell you if yours will be worth that.

Pretty typical for wholesalers to use different numbers than your own that are probably more aggressive.   

True, but (a) they were typically experienced investors, and (b) today's market includes record prices and high mortgage rates, which is a double whammy. 

- A 0% down, seller financed deal, typically equates to little to negative cashflow!

Plumbers typically charge $45–$200 per hour.

You don't provide enough data to know.Every product is only worth what you are willing to pay for it. 

However, required downpayments were typically 40-50%, and would be difficult without a residency visa.

These platforms typically have billing policies where you pay a per unit fee per month to the software and you get regular updates and support each month.There are a number of low-cost platforms available that are able to offer you a lower price by passing along some of the costs to your tenants (payment processing fees, applications, tenant screening, etc).

Quote from @Scott Trench: @Scott Johnson we typically don't delete forum posts, and I don't see a reason to make an exception here. 

Even if you have an absolutely solid home and its worth over 600k, in my area the most you can rent it for is $4000 MAX.