Dividing equity

A couple friends and I have just started to move past the ideas stage of our start-up and are getting to the point where we are trying to allocate ownership in the company. At this point in time, valuing our company seems quite arbitrary, but this is the ownership structure we have discussed: Founder 1: 20% Founder 2: 20% Founder 3: 20% Investor 1: $5000 for 2.5% Investor 2: $10,000 for 5% Remaining 32.5% : Options pool This gives our start-up an initial valuation of $200,000. Is this number too high, too low, or about right?