Even if it comes back clean, the tank will very likely need to come out and then the ground is retested to confirm that nothing 'happened' during the extraction.Assuming there are no other issues (i.e. additional tanks), one option to explore is to get the tank removal as part of the initial quote, you might get a better price, and not do the actual Phase 2 testing until after the tank is out so it only gets done, hopefully, once.

I am also in the process of having lead generating websites made (sellers and buyers).

I am going to generate my offer price based on ARV and work backwards from there (repair costs, etc). 

I work for our family’s fourth generation home building company on the sales side building custom homes on customers’ land all over Texas. 

Experienced investors will want to help you if you show initiative, drive, and genuine interest.

Your profile indicates you are not a newbie (your unit count is very close to my unit number) so you may have the experience to invest OOS successfully but I question if you have the capital for this investment and if you have run the numbers to realize how much you will be initially supplementing this investment.Good luck

I only except initial deposits through Chase Quick Pay, that sort of sets the table for 100% electronic payments.

Following this "Rule", you will never need any more money from other sources, since you will continuously be supplying your own...at will.Use your seed money, spend your profits...after, you've reinvested your initial profits to expand the original seed money. 

With the strong possibility of hard money funding and need for a large down payment, initial budgeting is limited.

Buying the tax certificate gives you No advantage in eventually owning the property.....it would later have to go to a Public tax deed auction, after you paid off All of the other outstanding certificates, probably 10 times your initial verticals purchase amount, then you’re still bidding against everyone else, less the credit for what you already have out of pocket.