Time-Life albums?????

Well, I have the Time-Life set (on vinyl) of the Wagner Ring cycle with Solti, the same recording made by London/Decca. Quiet surfaces, nice books, legendary performances but I believe that the originals of the records by Decca are far better pressings, with more dynamics in particular. I doubt if they had the original master tapes to make the transfers, as I believe that T-L licenses recordings from other companies, much as Musical Heritage Society does (perhaps someone can sorrect me if I'm wrong, but at least in the case of the Ring cycle it's clear that's what they did). Now if Time-Life releases CDs based on digital masters, while there is some degradation in copies from the original master (it usually is less, at least in theory, than with analog tapes), they might be closer to the original recordings from which they were licensed (they certainly are in the case of Musical Heritage Society) and might be a worthwhile purchase for sonics as well as performances, depending on the company that made the recording, the date of the recording and the artists involved. I would not buy the records strictly for their sonics, at least in vinyl, though, if that's what you're driving at--get them for the performances.

I have the Time/Life Giants of Jazz (or something like that) series -- twenty or more 3-LP sets in slip cases. They consist of recordings from the 20s to the early 50s and sound just fine, really good, in fact. Of course, given the age of the masters, you're buying mainly for the performances anyway. Wonderfully annotated as well -- track by track notes, photos, etc. Highly recommneded if you can find them. I don't think they ever made it to CD?

Well worth having. The historical booklets enclosed complete the experience. The original recording company can be discovered by checking the source of the copyright on a recording, or by seeing who the performers are, due to the long term relationship of performer, or orchestra, with a particular original label.
If the box is sealed, $1-2 per record, plus $2-3 extra for the mint NOS status would be fine for the box set. Of course, even cheaper is better, and you didn't mention what price you would be asked to pay by your seller.
Most recordings are enjoyable, but with such a series you are paying for musical enjoyment rather than audiophile excitement in every selection. The oppportunity to hear repertoire, and performers, and learn much about the composers, would be the main attraction. Among hundreds of selections there is variability due to original recording company.
The fun lies in becoming familiar with so many fine musical works, and past generations of worthy performers.
If the boxes are open, then check for cleanliness, and scratch-free status.
To start, check out a box in the named composer series, and another in the historical interval series to see if in this sampling there is the musical and audio quality you are hoping for.