Check around the gas tank for how the frame looks.
Especially the gap between the tank and the frame.
What part of the country are you? If the truck has lived anyplace where it snows, or near a beach, I would give it a good look-over for rust. Especially underneath (as Mudder said), and if possible, under the floor mats/carpet. A peak at the exhaust pipes can also give you a clue. Also, lots of flood damage vehicles out there right now. Beware. Any vehicle getting sold from the midwest, or a gulf coast state, should be looked at closely. Paying for a Carfax would be worth it.
I think the bottom line, is, well, the bottom line. How much is the truck, and how much money will be spent to get the truck where your brother will be happy with a good driver. With 200K it will most likely be time for a timing chain. Do you hear a rattle at start up? Oil in the radiator? What about other PM? Belts, hoses (water, vacuum, others), tune-up (plugs, wires, dizzy, PCV and grommet), color of brake/clutch fluid in the masters? Condition of brakes? How clean is it under the hood? Front crank seal leaking? Leaking from the bell housing (rear main seal)? Other leaks?
I guess my point is, ya, you could pick the truck up cheap ... then spend more than the purchase price getting it cleaned up and fixed. Granted, most if this stuff doesn't need to happen all at once and can be budgeted out over a few months. But, the money will get spent and you won't get it back on a resale.
You can get most stuff cheap at Rockauto.com. They sell Denso and AISIN aftermarket parts which are two of Toyota's OEM providers. Or you could just get cheap ... and get what you pay for. The other alternative would be one of the discount Toyota dealers you can find online. Usually these dealers offer parts 25% off list, plus shipping. Note that my discussion assumes your brother owns a wrench and socket set ... and knows how to use them. Paying mechanic rates will kill your wallet.
If your brother picks up the truck we are here to help. There is a wealth of RE knowledge on this site.