2002 O/D flashing 2 Diag. done both different diag.

Hello,I have a 2002 Ford Explorer XLT, 6cyl, 4x4, 71,000 mile. I had a friend preformed a diagnostic on my car for free but does not specialize in American care come up with a shift Soleniod problem and called ford to confirm the codes. They gave him a price on the part. I took it to a dealer and they came up with a finale code which is on of the codes that I got from my friend and said I need a new tranny. Who do I believe? Friend came up with;p0745: Cntrl Sol. A circuit malfunctionp0733: Gear 3 ratio Incorrectp0799: Cntrl Sol. C. CKT Intermittent = Shift Soleniod: Price $416.00Dealer; only code listed Quoting reportp0733 Perform pinpoint test and found line pressure at 75 psi in drive pass spec is 65 to 80 psi Perform electronic solnoid test and pass Concern is internal hardpart possible intermidate band or seal transmissionUnit should be replaced = $3800I have passed my 3 year warranty and currently paying car notes, while being unemployed. Really can not afford to pay for new tranny. No able to trade in while unemployed, and don't need a repo.Thanks for any idea's you may have!Red