Here is what I would do.
On the smoking TA-62, you already know it's gonna need a rebuild, so factor in at least $250.00 - $400.00 that the end user is gonna need to spend. That being said, that turbo I believe used to sell for around $999.99 way back in the day. If the turbo has a large shaft P-trim turbine wheel, the end user could have it upgraded to a TA-66 GT-Q if they wanted. It would be expensive, but it's possible. If it were me, I would try to sell it for $450.00 to $475.00. This would theoretically put the grand total after rebuild at around $700.00 - $875.00, which wouldn't be that bad. The end user might be able to get it upgrade to a TA-63 or TA-64 for just a few bucks more so don't forget that little tid bit of info. The TA-63, TA-64 and TA-66 GT-Q turbos have been good to go for quite awhile now and have been very popular with the stock appearing crowd. I wouldn't have it rebuilt back to a TA-62, as it's gonna be tough to sell it for more than $650.00. If you have to pay more than $175.00 to have it rebuilt, (which typically you will), it might not be worth it giving the 62 turbos reputation. You might call around and ask for an estimate for getting it upgraded to a 63, 64 or 66 tho. You could ask top dollar for a fresh TA-63, TA-64 or TA-66 GTQ that's for sure. Especially with proof in writting of the upgrade from a reputable turbo vendor like Limit or PTE.
On the PT54, that turbo a few years ago used to sell for $875.00 and currently sells for $921.99 according to Precisions current pricing directly from their website. Depending on how long the turbo has been off the car and sitting, the oil inside could have gummed up and or turned into carbon by now. So you have to keep that in mind when selling it and let whoever buys it know the full story. TE-44s and TA-49s typically are selling used for $450.00 - $650.00 depending on condition and mileage on it. If it's basically perfect, I would try to sell it for around $575.00 - $650.00.
On the high side you could get a combined total of $1,125.00 but just remember, there were some problems with the 62 turbos way back in the day. More so with the TE version than the TAs. One of the best ways to sell something like this revolves around your presentation, IE pictures, pictures, pictures. Pictures are worth a thousand words, especially when it comes to selling used turbos. Each post only allows 10 pictures per post so remember that too.
The best advice I can give you, other than have plenty of pictures, is to be 100% honest with everyone you talk to about the turbos. Every Turbo Buick owner/racer who's been into these cars for the past 10 years, knows the story behind the 62 turbos. I had a friend that ran one and had no problems with his during 3 years of owning it until he upgraded. Then again, I've had a couple of other friends who couldn't get one to live no matter what they did. It was really a crap shoot.
As far as picking a turbo for your goals of mid 10's, I would highly recommend the PT6776RS with a .63 A/R turbine housing. This turbo is capable of running mid 10's at decent boost levels with plenty to spare. Not too mention you only really need a converter that can flash stall to 3200 rpms.
Hope some of this helps and good luck with your sale.
Patrick
