I initially agreed with them because they said it would take about 3 weeks.  

ok, so fleshing out my plan for the future and thinking about getting the initial downpayment for my target, I figured I would come and ask about this:Would you invest in me at a rate of £10k for 50% of profits of the deal i put together, until the 10k is paid off, then 25% ongoing profits from the same property (buy and hold), and 10% of the *next* property?

A foreclosure can not be initiated until the redemption period is passed which also begins when the lien is issued.  

After mailing out the initial wave of say yellow letters, how long and how often is it recommended to send a follow up mailer?

We plan to use an investor agent (screening now) for buying & selling, at least initially.   

Closing costs on both the sale and purchase also factor into the calculation.1) purchase price plus your closing costs is your initial basis.purchase price $100,000.00purchase costs $2,000.00initial basis $102,000.002) depreciation reduces your basisvalue of improvements $80,000.00annual depreciation $2,909.09depreciation after 10 years $29,090.91basis after 10 years $72,909.093) closing costs on the sale reduce your net return from the saleselling price $150,000.00selling costs $3,000.00net selling price $147,000.004) net selling price less your basis is the total gaintotal gain $74,090.915) the gain is now split into unrecaptured depreciation and capital gainsuncaptured depreciation $29,090.91cap gain $45,000.006) And the tax is computed on eachrecapture rate 25%cap gains rate 15%recap tax $7,272.73capital gains tax $6,750.007) add them up to get the total tax billtotal tax $14,022.73Do notice that each year you had a deduction of just under $3000.  

So I'd only gain about $150 a month so it would take years to re coup my initial investment. 

questions:1.Should I go lower with initial offer?

I do have a full time job as an attorney, so my initial efforts will be limited to passive - or at least somewhat passive - investments.  

based on my initial evaluations it looks like a VR would generate more cash flow but I am making some assumptions on the vacancy rate and not sure how accurate they are.