Those are great little scopes in HD. I have a couple myself. I use the newer 25x LER eyepieces on mine. the 30W is excellent as well- but it's not having that great 30+mm eye relief. It's a little easier to get behind a straight scope with the LER eyepiece also...Just depends what works for you I guess.
The older 25x eypieces really don't have any value...I think they're close to terrible

I believe they were standard issue on the TS-614?
Rotherbirder is right, they're a lightweight scope and if you knock one over or drop it hard you might have issues. They say "water-resistant" I think somewhere between water resistant and outright water-proof.
Are you looking to sell your 614 or just curious on value? Value wise, I purchased a minty 613 on Ebay UK last fall for $250 w/the old style eyepiece, might be a starting point? If you have a use for a spotter, buy a modern eyepiece. 25x or 30W. Dont get a zoom....You wont gain anything over 30x.
J Ring why do you say the SV82 is rather strange? I thought it was a relatively good idea by kowa. The 821/823 was/is a very popular glass in the target shooting world, and when they did away with the 820x series they kept the TSN-82 "Shooters Version" around just for that clientele. They could have just as easily done away with the 820x style entirely when they did away with the larger dia eyepieces. I'm kinda glad they didnt...I happen to own both an older 821 and the SV... I do find the SV slightly brighter? Maybe improved coatings?