hello all i am new to the toyota world and have always wanted one and i have found one in my local listings and before i buy i would just like some help in what to look for and what to look at before i drop 3500 on this cool little truck

it has 295000 miles and the owner claims he rebuilt the turbo, but it looks like it has never been removed from the exhaust mannifold, i hav not done a compression test on it and it does seem to have a leek in the front of he head right at the head gasket, it has a leeking transfer case, but besides that it is a nice clean little truck and it doesnt smoke so im decently confidant the turbo is in decent shape

i am mostly wondering how much it would cost to rebuild it and where i should get parts

any suggestions?