From experience Socata seem adverse to using standard AGS so very often you will find that instead of being able to buy 'of the shelf items' you have to buy manufacturer's parts. Fuel & Oil hoses?
It depends on which ones.
The hose between the fuel pump and the carb/fuel servo, and the hose between the latter and the injector spider, are standard Lyco parts which any hose shop can make up for about £40. If you get Teflon ones (£40) they are good for life (on a TB).
Same for the oil cooler hoses, IIRC.
Airframe-specific flexible hoses, 2 or 3 of those, are a "Socata special" which use ISO thread fittings, L43-215 type, and these fittings are expensive. Such a hose costs about £400 from Socata, or about £200 if you get them made by a hose shop (I have done this, email me for the details) which can get the fittings. Again, on a TB aircraft, Teflon hoses have no life limit.
AFAIK, the only time any of these hoses are a mandatory replacement is on the engine ones which are replaced at engine overhaul i.e. 2000hrs+. Not a significant problem considering the cost of an OH, and only 1 or 2 hoses.
To be fair, this
is a real issue but only because maintenance shops tend to be slightly lazy and the UK ones tend to blindly buy parts from Air Touring. Anybody with initiative can easily find the parts from non-Socata sources. Socata have tried to make it hard by giving every last nut and washer a special P/N and most are not cross-referenced to the real ones. The idea, of course, is that the Socata dealer buys all parts from Socata.
But the whole GA business works on this kind of scam - they rely on lack of initiative and ignorance. Superficially it's easier on an N-reg because an 8130-3 is good but an 8130-3 (or any other traceability document whatsoever) is equally good for a non-PT G-reg; ref CAA AN-14 (which most people don't want you to know).
A large part of reducing the operating cost of a plane, especially an old one, is known as a "brain", and not simply buying everything from the dealer. True for a Socata, a Cessna, a Piper, everybody.
But there is no doubt that if you get stuck at Kathmandu you are better off with a Cessna. But.... since the cost of unscheduled maintenance depends heavily on the general condition of the plane, and in the later years being made up largely of airframe parts, so much depends on the plane's history.
Jxk - I will send you an email or a PM with some info.