$8000 for a stock frame with all stock suspension pieces. Seems a little expensive if you ask me. Here's what you do. Buy a used 400EX for $3000. Buy a 1-2 year old used CR250 for $3000. Rebuild the top end on the CR for about $200. Have someone build you an exhaust for $500. Sell the stock 400EX engine for $800-$1000 and then sell the remaining CR for $1000. It's just cost you $6700 to build Servicehonda's 250R versus their $8000 asking price. Not only that but you've pocketed at least $1800 from the sale of the old parts. That drops what you've actually paid out to $4900. Then you can buy aftermarket shocks, a-arms, swinger and axle.
Which would you rather have? A stock chassis 400EX with a CR250 motor in it for $8000 that servicehonda built for you or a 400EX frame powered by a CR250 motor with PEP shocks, Laeger a-arms, RPM swingarm, RPM axle, beadlocks and Razr's for $8000?
2001 400EX - J.E. 416 kit, XR400 cam, Full Yoshimua system, Twin Air filter, PRM swing arm skid plate, AC pro pegs, Razrs 2 front and back, Custom Axis front and rear, Tag 2's.