Not an expert, but feel obligated to give my 2c. By trade I am a golf course superintendent at a 36 hole facility. We allocate between 20-30K in our budget annualy for cartpath repairs. That being said, we have over 4 miles of asphalt cartpath. All you would need for an RC runway is a solid 4" base of grade 8 limestone ( aka CA-6 ). And at most 3" of asphalt on top. Those are the numbers we go by which hold up to daily golf cart traffic. The only reason we have to spend so much money is due to freeze/thaw cycles we get in Chicagoland. In an earlier post 70K was mentioned, Pardon my reaction, but that is frikkin ludicrus. Do yoursaelf a favor and contact a local golf course superintendent at a higher end club that has money to spend. Chances are they have contacts with an independent 'shaper' who will do all the coring and grading at pennies on the doller compared to larger companies. Then you can get someone to come and lay the asphalt. Again, just my 2c, but a phone call couldn't hurt. BTW, once you solidify your runway measurments, any and all companies will give you a free estimate.