We have a 1998 V70 wagon with the low pressure turbo 2.3 liter engine. At 95k miles it seems to be using a fair amount of oil, as in a quart every 1500 miles or so (primarily stop and go driving around town.) There is no sign of a leak or smoke - my theory, based on modest mechanical knowledge, is that the turbo oil seals have failed and the oil is going straight into the exhaust as vapor or something. Any ideas?

As a related question, what is the typical lifespan of the turbocharger unit and what can I expect to pay for replacement/service? Can the job be done at home? I heard the bearings as the thing wound down the other day. Looks like it's in a pretty miserable spot.